Update linkpreviewer to minimise the number of resizes.
- There is now a placeholder loading element to hold space while the data is obtained
- The component starts with a set size but can be expanded to see the whole item.
- The expand/contract button is only visible on hover
- The default size is picked to show 3 lines of text (1 heading and 2 description, 2 heading and 1 description, etc)
This is designed to help with the timeline scroll jumping CCBUG: 463235 by minimizing the amount of resizing for items in the timeline.
Before

After when compressed

After When expanded

After Loading

Implement folding sections for multiple consecutive state events. This also reworks some of the aggregated text output:
- Only new days cause a new section
- The aggregated text starts with either a single username or n users
- If the same user did the same action mutltiple times it will be in the aggregated text a user did x n times
- When there are multiple authors in a block with multiple state event types it will use or rather than and before the last event. e.g 3 user left the room or joined the room.
Folded

Unfolded

Implements network/neochat#90
This is mostly a stylistic rework of the chatbar but there are some buxfixes / improvements in here as well. The aim was to make the chatbar so it's size was managed in the same manner as the timeline in both bubble and compactmode in the same manner as network/neochat!476.
The other features are:
- Replies, attachments and edits now look like they are inside the chatbar and use a similar styling to edits in message bubbles
- Replies and edits now part of the message so they arte part of the ScrollView and will scroll away when the text is long
- ~~The emoji picker is now a popup so it doesn't mess with the timeline layout when activated~~ (done in network/neochat!697)
- ~~Emoji dialog is now no longer required as the picker itself is a popup now~~ (no longer the case see above)
- The scrollbar now sits on the right of the chatbar actions rather than weirdly to the left
- The action icons will always stay in the same place even as the chatbar gets taller
Updated\

Scrollbar behaviour before

Scrollbar behaviour after
