[NEW] Shows file list from a room

Merge custom actions if any (ones other than the defaults) to message actions and remove test action

[CHORE] Realm Stetho - Increase table view data limit

[DOCS] Update ISSUE_TEMPLATE.md

[DOCS] Update CONTRIBUTING.md

[CHORE] Increment release & build number: 1.0.21 - 41

Clear Realm on asynchronous thread and also clear cookies

Multiple minor issues fixes

Use trySetError instead of tryError on DDPClientImpl since this class is usually used wrapped on Rx subscriptions when the first will throw an exception probably leading to an unexpected behavior or crash with a compose exception and the latter will just bail out