* Take into account homeserver capabilities: add `HomeserverCapabilitiesProvider` to check if the HS allows changing the user's display name or avatar. Also, modify the edit user profile screen to reflect these values.
* Add `/myavatar` command. Filter both `/nick` and `/myavatar` commands based on the homeserver capabilities.
* Update screenshots
* Assume the use can change their display name and avatar url if the capabilities check fails: if they try to change those, the HS will return an error anyway.
* Disable also `/myroomname` and `/myroomavatar` based on the HS capabilities.
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Co-authored-by: ElementBot <android@element.io>
* Add support for slash commands
* Update screenshots
* Rename module `slash` to `slashcommands`
* Rename `SlashCommand` to `SlashCommandService`
* Introduce MsgType in order to send text message with a different msgtype value.
* Format file and add parameter names, add default values and cleanup
* Add isSupported parameter to filter out unsupported yet commands.
* Slash commands: disable suggestions if the feature is disabled.
* Fix sending shrug command.
* Add missing test on SuggestionsProcessor
* Add tests on MessageComposerPresenter about slash command.
* Fix import ordering
* Add missing tests on CommandExecutor
* Add missing tests in MarkdownTextEditorStateTest
* Slash commands: Improve code when sending message with prefix.
* Slash commands: Add support for /unflip
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Co-authored-by: ElementBot <android@element.io>
