On the `<converse-chat-content>` element. This removes the need for all
the manual scrolling.
Firefox finally supports this feature. Unfortunately Firefox ESR doesn't
yet, but I can't wait anymore.
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
- Move top-level functinos to utils files
- Get rid of unused/obsolete overrides
- Only import components there where they're used
- Bump version in package.json
It's misleading because it shows before MAM has finished (which also causes
flashing)
Showing it only after MAM has finished would be preferable but too much
work, so I'm removing it for now.