AGS 4: Completely remove Global Messages and Room Messages

[ivan-mogilko]

This completely removes any functionality related to deprecated Global Messages and Room Messages from both Editor and Engine.

For built-in GUI dialogs that relied on global messages added small array of hardcoded strings. The downside is that these cannot be translated now. But these dialogs are not suitable for the proper production release anyway.

On a side note, we might eventually require a set of messages for certain engine behavior, that user could provide custom values and possibly translations. For purposes like error and warning reporting. In such case we could recreate functionality, but make these messages have strictly predefined purposes (unlike global msg which could be used freely for custom means).

TODO: fix data format for game data and saves, because they currently contain unused large fixed arrays of ints.

[ericoporto]

Hey, the failure on CI is because there is a test that in the editor that checks if the room XML is kept, so you would need to adjust that.

edit: it's fixed!

[ivan-mogilko]

Had to fix game loading, in case there were still messages found in the old compiled data.

[ericoporto]

Nice, after merging, the APIs cut here can be updated in the checklist in #1810

Edit: erh, actually even though you comment about this in your last message in the thread, the list doesn't include the global message stuff.