Add servers to MobX.

Add Channel object.

i18n invites page.
Polish the bans page.

Revert mobile change.
Messages: Add channel id matching.

Sidebar: Show home button on mobile.

Home Sidebar: Remove top bar.

Don't pass dispatcher in, just provide it globally.
Fix: Allow clicking through to profile from server sidebar.

Can now collapse server categories.
Client remembers collapse state, incl. advanced appearance settings.

- replaced many uses of `as any` with another more specific cast `as T`
- filled in missing typed for items that needed to be typed
  - new runtime code was added where necessary to satisfy the new types with comments
- added missing theme variable "sidebar-active" to the Theme variables
- forms using `react-hook-form` are now typechecked
- changed some instances of `target` into `currentTarget` while removing `as any` assertions

Re-design status context menu.

Add rounded corners to sidebar.

Fix strokes on home sidebar.
Add tooltips on servers.
Fix reply SVG direction.

Modals: Allow all modals to be closed by ESC (permitting).
Fix: Handle closing DMs properly. Stop propagation too.

Feature: Remember what channel was opened last.
Channels: ESC to focus message box / cancel editing.

Servers: Fix various issues relating to voice channels.

Add profile links / app links back.
Add quoting / mentioning back.