* Fix#2102 - Implement hotkeys
Hotkeys on status list:
- r to reply
- m to mention author
- f to favourite
- b to boost
- enter to open status
- p to open author's profile
- up or k to move up in the list
- down or j to move down in the list
- 1-9 to focus a status in one of the columns
- n to focus the compose textarea
- alt+n to start a brand new toot
- backspace to navigate back
* Add navigational hotkeys
The key g followed by:
- s: start
- h: home
- n: notifications
- l: local timeline
- t: federated timeline
- f: favourites
- u: own profile
- p: pinned toots
- b: blocked users
- m: muted users
* Add hotkey for focusing search, make escape un-focus compose/search
* Fix focusing notifications column, fix hotkeys in compose textarea
* Fix behavior while the button is invisible
e.g. pointer cursor, couldn't open contextmenu
* Avoid rendering the button to remove blank space if no more items are available or no items are rendered
Resolved:
* Lot of redundant renders while mouse moving
* Scroll jumping when timeline loaded
* Scroll position isn't kept when statuses below the scrollTop was deleted then new status arrived
Unresolved:
* Scroll position isn't kept when statuses over the scrollTop was deleted then new status arrived
-> It needs to know which statuses are over the scrollTop
* New status indicator should be active when new statuses arrived while mouse moved recently
-> It needs a) update indicator in ScrollableList, or b) set scrollTop status while mouse moving
