Verify all non `pocketmine.` prefixed translations are present in vanilla translation files

[dktapps]

Any string that isn't prefixed by pocketmine. is expected to be automatically translated by the client, if given the opportunity.

We allow this because it avoids the need for the server to match the client and server language for some translations. However, it's problematic when translations are changed or removed in vanilla, because then issues like pmmp/PocketMine-MP#5471 crop up, or various other issues where translation keys have been altered (e.g. the old commands.gamemode.success bug in 2016).

We can possibly detect these problems by validating the translations against those provided publicly by Mojang here: https://github.com/Mojang/bedrock-samples/tree/main/resource_pack/texts

While we can't include these files in PocketMine-MP directly due to licensing incompatibility, we can use them for validating our own.