Highlight incompatible mods recursively

[HebaruSan]

Problem

If you try to install RP-1 on KSP 1.12 without following the instructions (which call for marking KSP 1.11 compatible), you'll find you can't install it, and the reason is not apparent on the Relationships tab, which has increasingly become the place to investigate compatibility:

If you expand dependencies (or try to install the depending mod from the Versions tab), you can discover that RP-0 depends on SXTContinued, which depends on Firespitter, which is only compatible up to KSP 1.11:

Noted in KSP-CKAN/NetKAN#9306.

Cause

The relationships tab's red highlighting only indicates whether the mod itself is compatible, not including its dependencies. It doesn't load all relationships recursively, for performance reasons; instead, it only loads two generations, so it can show which nodes are expandable, and then more generations are loaded if the user expands a node. This structure means that it may not know whether a mod is indirectly incompatible until multiple layers have been expanded and the user finds the issue.

But another component does know all mods' recursive compatibility: the CompatibilitySorter from #2963.

Changes

• Now the registry provides IdentifierCompatible to allow quick recursive compatibility checks via the CompatibilitySorter object
• Now the relationships tab uses Registry.IdentifierCompatible to check compatibility instead of simple game version checks

This causes SXTContinued to be highlighted red even though it's individually compatible, and you can still expand it to see Firespitter:

[techman83]

That's a good QoL improvement!