UX improvements + Move to Vue 3

[Troplo]

• Move to Vue 3 (Only things that needed to be changed was removal of Vue.set, new Vue -> createApp, and created -> mounted on lobby.)
• New "show JavaScript errors" button to show any exceptions thrown by user scripts
• Auto scroll implementation to scroll page to the bottom when a new message is sent by user, form interaction, or if the page is near the bottom. Toolbar shown when page has auto scroll prevention
• Change script/CSS imports to have prepended / so page layout isn't broken on links such as /group4/test
• Disable settings auto-open on mobile
• Add settings cog icon in header for mobile
• Change clear room messages to red to indicate destructive action (with ... to indicate confirmation is required)
• Allow enter key for clear room message confirmation