Added __on_player_message event (#1312)

* Added __on_player_sends_message event

* Docs for chat message event

* Rename to __on_player_message

* Editor support

* Added event to event_test app

* Update docs/scarpet/api/Events.md

Co-authored-by: gnembon <41132274+gnembon@users.noreply.github.com>

docs/scarpet/api/Events.md

@@ -275,6 +275,9 @@ Triggered when the player has successfully logged in and was placed in the game.
 ### `__on_player_disconnects(player, reason)`
 Triggered when a player sends a disconnect package or is forcefully disconnected from the server.
 
+### `__on_player_message(player, message)`
+Triggered when a player sends a chat message or runs a command.
+
 ### `__on_statistic(player, category, event, value)`
 Triggered when a player statistic changes. Doesn't notify on periodic an rhythmic events, i.e. 
 `time_since_death`, `time_since_rest`, and `played_one_minute` since these are triggered every tick. Event