v0.17.4

• (bridge) Started rejecting reusing access tokens when enabling double puppeting. Reuse is detected by presence of encryption keys on the device.
• (client.api) Added wrapper method for the /context API.
• (api, errors) Implemented new error codes from MSC3848.
• (types) Disabled deserializing m.direct content (it didn't work and it wasn't really necessary).
• (client.state_store) Updated set_encryption_info to allow raw dicts. This fixes the bug where sending a m.room.encryption event with a raw dict as the content would throw an error from the state store.
• (crypto) Fixed error when fetching keys for user with no cross-signing keys (thanks to @maltee1 in #109).