Unchanged files/outputs are deleted from staging and then generated/copied back in

[robojumper]

Examples:

1. Localization files are reverted to their UTF-8 versions in staging and then converted to UTF-16 again (lwotc, ~3 seconds, also see #34)
2. Cooking outputs and IncludeMissingUncooked packages are removed from staging and then copied back (CovertInfiltration, ~25MB)
3. ModShaderCache is deleted and added back from the BuildCache
4. Compiled script packages are removed from staging and then copied back in (lwotc, ~13MB)

Other incremental issues are going to have a far bigger impact for now because files aren't egregiously large, but especially when projects with large sets of assets like lwotc start cooking packages, 2. could add up and cause dozens of megabytes to be copied every single run.

This may require a move away from a full robocopy /mir call towards a treatment of individual folders in the project.

[Xymanek]

Some relevant notes:

• The shader precompiler must see the files inside ContentForCook, otherwise we will be missing out on those materials
• The shader precompiler doesn't care about the folder layout - as long as the package is somewhere inside the mod's folder in SDK, the shader precompiler will process it
• Collection maps are created (duplicated from the template in X2MBC) before each asset cooker invocation
• Due to the above, the staged directory is included into the SDK currently (so we don't screw around with the original project). However, #11 should solve this issue