Follows the same pattern as PerformJoin on roomserver (no error return).
Also return the right format for incompatible room version errors.
Makes a bunch of tests pass!
* Add a way to force federationsender to retry sending transactions
And use it in P2P mode when we pick up new nodes.
* Linting
* Use atomic bool to stop us blocking on the channel
* Add PerformJoin template
* Try roomserver perform join
* Send correct server name to FS API
* Pass through content, try to handle multiple server names
* Fix local server checks
* Don't refer to non-existent error
* Add directory lookups of aliases
* Remove unneeded parameters
* Don't repeat join events into the roomserver
* Unmarshal the content, that would help
* Check if the user is already in the room in the fedeationapi too
* Return incompatible room version error
* Use Membership, don't try more servers than needed
* Review comments, make FS API take list of servernames, dedupe them, break out of loop properly on success
* Tweaks
* Define an input API for the federationsender
* Wiring for rooomserver input API and federation sender input API
* Whoops, commit common too
* Merge input API into query API
* Rename FederationSenderQueryAPI to FederationSenderInternalAPI
* Fix dendritejs
* Rename Input to Perform
* Fix a couple of inputs -> performs
* Remove needless storage interface, add comments
