Merged PR 88411: Fix html self closing issues

**Issue**
Q&A elements are rendered in a wrong way.

**Reason**
Some div elements are marked with self-closing.
According to the HTML5 spec, tags that cannot have any contents (known as void elements) can be self-closing*. This includes the following tags:

**Resolution**
_Only void elements can be self closing. from HTML5 spec, void elements are:_
area, base, br, col, embed, hr, img, input, link, meta, param, source, track, wbr

**Copied from HTML5 SPEC:**
Tags are used to delimit the start and end of elements in the markup. Raw text, escapable raw text, and normal elements have a start tag to indicate where they begin, and an end tag to indicate where they end. The start and end tags of certain normal elements can be omitted, as described below in the section on optional tags. Those that cannot be omitted must not be omitted. Void elements only have a start tag; end tags must not be specified for void elements. Foreign elements must either have a start tag and an end tag, or a start tag that is marked as self-closing, in which case they must not have an end tag.

**References:**
https://html.spec.whatwg.org/multipage/syntax.html#void-elements
https://stackoverflow.com/questions/3558119/are-non-void-self-closing-tags-valid-in-html5

Related work items: #365457

Author: ali-hamud

demo/code-demo/log_window.html

@@ -8,5 +8,5 @@
             <img src="images\clear.png"/> Clear
         </button>
     </div>
-    <textarea id="txtResponse" class="responseTextArea" />
+    <textarea id="txtResponse" class="responseTextArea"></textarea>
 </div>

demo/code-demo/settings_embed.html

@@ -4,7 +4,7 @@ <h4>Embed Report</h4>
     </div>
 
     <h8>Select mode to embed your report in:</h8>
-    <div class="spacer" />
+    <div class="spacer"></div>
     <div id="modeSelector">
         <div onclick="OpenViewMode();"><input type="radio" name="embedMode" value="view" checked="checked"> View mode </input></div>
         <div onclick="OpenEditMode();"><input type="radio" name="embedMode" value="edit"> Edit mode</input></div>
@@ -13,7 +13,7 @@ <h4>Embed Report</h4>
 
     <div id="embedModeInput">
         <h8>Fill in the fields below to get the code to embed your report.</h8>
-        <div class="spacer" />
+        <div class="spacer"></div>
 
         <div class="inputLine">
             <div class="inputLineTitle">Embed Token</div>
@@ -31,7 +31,7 @@ <h4>Embed Report</h4>
 
     <div id="createModeInput">
         <h8>Fill in the fields below to get the code to embed your report.</h8>
-        <div class="spacer" />
+        <div class="spacer"></div>
 
         <div class="inputLine">
             <div class="inputLineTitle">Embed Token</div>

demo/v2-demo/log_window.html

@@ -9,6 +9,6 @@
         </button>
     </div>
     <div class="responseTextAreaWrapper">
-        <textarea id="txtResponse" class="responseTextArea" />
+        <textarea id="txtResponse" class="responseTextArea"></textarea>
     </div>
 </div>

demo/v2-demo/settings_embed_dashboard.html

@@ -12,10 +12,10 @@
                 <span class="checkmark"></span></div>
             </label>
         </div>
-        <div class="spacer" />
+        <div class="spacer"></div>
         <div id="embedModeInput">
             <h8>Fill in the fields below to get the code to embed your dashboard.</h8>
-            <div class="spacer" />
+            <div class="spacer"></div>
 
             <div class="inputLine">
                 <div class="inputLineTitle">Embed Token</div>

demo/v2-demo/settings_embed_qna.html

@@ -1,7 +1,7 @@
 <div id="qna-embed-table">
     <div id="wrapper-settings-div">
         <h8>Select mode to embed Q&A in:</h8>
-        <div class="spacer" />
+        <div class="spacer"></div>
         <div id="modeSelector">
             <label class="radioContainer">
                 <div onclick="ToggleQuestionBox(false);"><input type="radio" name="qnaMode" value="Interactive" id="InteractiveNoQuestion"> Show Q&A </input>
@@ -19,13 +19,13 @@
 
         <div id="questionDiv">
             <h8>Q&A input question</h8>
-            <div class="spacer" />
+            <div class="spacer"></div>
             <input type="text" id="txtQuestion" style="width: 100%" value="2014 total units YTD var % by month, manufacturer as clustered column chart" onchange="UpdateSession(this, SessionKeys.QnaQuestion);"/>
         </div>
 
         <div id="embedModeInput">
             <div class="noOverflow"><h8>Fill in the fields below to get the code to embed your Q&A.</h8></div>
-            <div class="spacer" />
+            <div class="spacer"></div>
 
             <div class="inputLine">
                 <div class="inputLineTitle">Embed Token</div>

demo/v2-demo/settings_embed_report.html

@@ -42,7 +42,7 @@
         </div>
 
         <div class="noOverflow"><h8>Fill in the fields below to get the code to embed your report</h8></div>
-        <div class="spacer" />
+        <div class="spacer"></div>
         <div id="embedModeInput">
             <div class="inputLine">
                 <div class="inputLineTitle">Embed Token</div>

demo/v2-demo/settings_embed_tile.html

@@ -12,10 +12,10 @@
                 <span class="checkmark"></span></div>
             </label>
         </div>
-        <div class="spacer" />
+        <div class="spacer"></div>
         <div id="embedModeInput">
             <h8>Fill in the fields below to get the code to embed your tile.</h8>
-            <div class="spacer" />
+            <div class="spacer"></div>
 
             <div class="inputLine">
                 <div class="inputLineTitle">Embed Token</div>

demo/v2-demo/settings_embed_visual.html

@@ -13,9 +13,9 @@
             </label>
         </div>
 
-        <div class="spacer" />
+        <div class="spacer"></div>
         <h8>Fill in the fields below to get the code to embed your visual</h8>
-        <div class="spacer" />
+        <div class="spacer"></div>
         <div id="embedModeInput">
             <div class="inputLine">
                 <div class="inputLineTitle">Embed Token</div>