v0.7.0

[0.7.0] -- 2022-03-09

• Allow querying a reusable server url for the current server
• Explicit SSO identity providers
• Reasons for redactions
• Treat all exceptions as errors
• Support hidden read receipts
• Support fetching the current room state
• Stabilize registration tokens
• Widget events
• Support the space hierarchy API
• Allow checking a usernames availability
• Allow querying registration flows ahead of time
• Properly validate matrix ids
• Fix ambiguous conversion of pushrule actions
• Reduce copies for pushrules
• Remove mentions of Boost.ASIO
• Fix documentation