* Handle case of encryption key for an index to be undefined
As per https://github.com/matrix-org/matrix-js-sdk/pull/4423 the key can be undefined and so we should handle this rather than waiting for SubtleCrypto.importKey() to fail.
* Use release version of matrix-js-sdk
Diff is baa6d13506...v34.7.0
* Use RTCSession. reemitEncryptionKeys()
* Add some test coverage whilst we are here
* Add some test coverage whilst we are here
* Lint
* Enable lint rules for Promise handling to discourage misuse of them.
Squashed all of Hugh's commits into one.
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Co-authored-by: Hugh Nimmo-Smith <hughns@element.io>
The auto ratcheting sets the keys and so looks like it can clobber
us setting a key from the app if they race, so just disable it, at
least for now - we aren't using it.
