v0.22.1

• (crypto) Added automatic cleanup when there are too many olm sessions with a single device.
• (crypto) Added helper for getting cached device list with cross-signing status.
• (crypto/verificationhelper) Added interface for persisting the state of in-progress verifications.
• (client) Added GetMutualRooms wrapper for MSC2666.
• (client) Switched JoinRoom to use the via query param instead of server_name as per MSC4156.
• (bridgev2/commands) Fixed pm command not actually starting the chat.
• (bridgev2/interface) Added separate network API interface for starting chats with a Matrix ghost user. This allows treating internal user IDs differently than arbitrary user-input strings.
• (bridgev2/crypto) Added support for MSC4190 (thanks to @onestacked in #288).