Cleanup several views

Changes

Landing page

• Remove 'HomeActionsComponent' and move functionality to 'HomeComponent'
• Code optimizations
• Remove card
• Make 'create-session'-btn more inconspicuous
• Fix header text position

Room-join improvements

• Customize the button appearance
• Add animation to button which appears when hovering the button after the user has entered 8 digits

Room views

• Remove and cleanup unused CSS stylings
• Move 'copy-url' functionality to QRCodeComponent
• Change naming of 'Questions' to 'Comments'
• Make room pages fully responsive with texts
• Fix contentGroup badge
• Text reduction

Header and footer

• Set footers color to background-color
• Show footer descriptions on devices which are wider than 600px
• Add new column to users-menu 'Go to home'
• CSS refactoring

User view

• Replace table with a list
• Realign list items
• Add options 'Delete session' and 'Settings' to owner rooms

Comment view

• Fix presentation dialog exit button stylings
• Set comments height to 'auto' to avoid scrolling within a comment
• Make comments body responsive
• Fix animation bug of fixed 'button-bar'
• Allow a longer difference before the 'scrollToTop'-button appears
• CSS refctoring

Content creation

• Remove dialog for editing an answer
• Add an inline text field for editing an answer

Fix minor bugs in settings

• Get shortId from route
• Remove not working function 'addToHistory' for moderators

Fix minor styling issues

• Fix color of confirm buttons in dialogs
• Improve Feedback lock/unlock animation
• Style scrollbar according to theme
• Fix primary/secondary color of 'light-theme