[WE] Apply block migrations to blocks in blueprint palette

[Argmaster]

Migrations are available in migrations.zig, but are not used for palettes while loading blueprints.
This is problematic, because in theory we should re-write the migrated blueprint, since after some time old migrations will be removed.

[BoySanic]

I threw together an attempted fix in #2080

The approach is to construct an Palette object for use in the migrations, apply the migrations, then continue.

I'm unsure whether this issue also meant to re-save those blueprints with the applied migrations, if any had been applied. And I'd guess if that were the case we'd also only want to save the blueprints post-migration if they're different than the input.

Please let me know if I'm on the right track or how you'd adjust my approach in the PR :)

[IntegratedQuantum]

As of #2278 this is now actually affecting the base game. We need a solution for this soon.

[IntegratedQuantum]

I have decided to go for the quick solution which always re-applies the migrations each time the blueprint is loaded.

This is problematic, because in theory we should re-write the migrated blueprint, since after some time old migrations will be removed.

I think we should worry about that, when it actually becomes something that we need to do.

[Auseawesome]

I think we should worry about that, when it actually becomes something that we need to do.

I would just say throw into the debug log when the palette is used so devs can fix it. Doesn't really need to be automatic, does it?

[IntegratedQuantum]

Yes, I did that too.