* add /me handling
* use typeguards to avoid fighting TS
* improve clarity and use of typeguards
* add createMessageContent tests
* remove completed TODO
* improve comments
* remove duplication and renaming of argument
* pass handleCommand prop down and use it in WysiwygAutocomplete
* allow a command to generate a query from buildQuery
* port command functionality into the sendMessage util
* tidy up comments
* remove use of shouldSend and update comments
* remove console log
* make logic more explicit and amend comment
* uncomment replyToEvent block
* update util test
* remove commented out test
* use local text over import from current composer
* expand tests
* expand tests
* handle the FocusAComposer action for the wysiwyg composer
* remove TODO comment
* remove TODO
* test for action dispatch
* fix failing tests
* tidy up tests
* fix TS error and improve typing
* fix TS error
* amend return types for sendMessage, editMessage
* fix null content TS error
* fix another null content TS error
* use as to correct final TS error
* remove undefined argument
* try to fix TS errors for editMessage function usage
* tidy up
* add TODO
* improve comments
* update comment
* allows switching between modes that retains formatting
* updates rich text composer dependency to 0.13.0 (@matrix-org/matrix-wysiwyg)
* improves handling of enter keypresses when ctrlEnterTosend setting is true in plain text editor
* changes the message event content when using the new editor
* adds tests for the changes to the plain text editor
