Migrate desktop-only types to quorum-shared

[lamat1111]

Several desktop features have types not yet in the shared package. I'd like to batch them into one PR:

• Thread types - ThreadMeta, ThreadMessage, ChannelThread, plus thread fields on Message, PostMessage, Bookmark, Space, Channel
• Space Tags types - SpaceTag, BroadcastSpaceTag, plus fields on Space, SpaceMember, UpdateProfileMessage, UserConfig
• SpaceMember.joinedAt - for new member badge (Add joinedAt to SpaceMember type #1)
• Possibly more after a full audit

All additions are optional fields or new types - non-breaking for mobile.

Separately:

• Primitives migration is already approved.
• Should I also start looking at utility functions (~90% are portable) and hooks (need adapter refactoring)?

@CassOnMars

[CassOnMars]

Go for it!

[lamat1111]

Updates:

• Types migration DONE Shared types migration from quorum-desktop #3
• Primitives migration DONE Shared primitives migration from quorum-desktop #4
• Utils and hooks migration TO DO