This prevents it from being persisted across page loads and makes more
sense logically.
Also move markScrolled to utils and MUC unread messages indicator to bottom panel.
More work on making bottom panel sub-components declarative
- Handle auto-completion in the converse-muc-message-form element
- Make message limit indicator a component
- Rename template
Had to make various other changes due to incompatibilities.
- Use the new `lit` package instead of `lit-html` or `lit-element`
- Drop `haunted` since it breaks the rules by specifying `type: module`
but then doesn't import with file extensions
- Use Sass Dart instead of node-sass (fixes#2445)
- Upgrade Karma