Handle command completions in RTE (#10521)

* 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

src/components/views/rooms/wysiwyg_composer/utils/autocomplete.ts

@@ -29,9 +29,8 @@ import * as Avatar from "../../../../../Avatar";
  * with @ for a user query, # for a room or space query
  */
 export function buildQuery(suggestion: MappedSuggestion | null): string {
-    if (!suggestion || !suggestion.keyChar || suggestion.type === "command") {
+    if (!suggestion || !suggestion.keyChar) {
         // if we have an empty key character, we do not build a query
-        // TODO implement the command functionality
         return "";
     }