[MM-38216] Add API endpoint and adapt search to allow multi-team search (#18371)

* Add API endpoint and adapt search to allow multi-team search

* Refactor handler, refactor sql query to use squirrel, rename app and store functions and add tests

* Fix lint

* Fix search engines and remove unneeded comments

* Fix test

* Remove user from channel after test

app/plugin_api.go

@@ -512,7 +512,7 @@ func (api *PluginAPI) SearchPostsInTeamForUser(teamID string, userID string, sea
 		includeDeletedChannels = *searchParams.IncludeDeletedChannels
 	}
 
-	return api.app.SearchPostsInTeamForUser(api.ctx, terms, userID, teamID, isOrSearch, includeDeletedChannels, timeZoneOffset, page, perPage)
+	return api.app.SearchPostsForUser(api.ctx, terms, userID, teamID, isOrSearch, includeDeletedChannels, timeZoneOffset, page, perPage)
 }
 
 func (api *PluginAPI) AddChannelMember(channelID, userID string) (*model.ChannelMember, *model.AppError) {