Enable TypeSubsumptionCache for IDE use

[majocha]

Description

This builds upon Vlad's work from #18190 and #17668, extending the fix for #17501 into incremental compilation / typecheck in IDE editor.

This is resubmitted and cleaned up #18468.

Currently the feature is enabled only for lang version preview.
As for testing, this is mostly tested by dogfooding. This repo builds fine and the tests that do use preview version pass.
I also tested manually the scenario from original issue. It is fixed now also in the IDE.

Added some basic cache tests as a starting point, too.

Performance considerations:
The goals here are:

• do keep the performance gain from original fix
• do not degrade performance in typical scenarios, including incremental and stand-alone compilation.

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[vzarytovskii]

That's great! Thanks a tonne for taking over it and making it actually work!

[majocha]

@T-Gro I went with your suggestion of MailboxProcessor, it made the code way better. I just need to test it a bit.

[majocha]

Quick smoke test to make sure everything works as before in the IDE:

Looks good, no failures and no capacity overruns.

[majocha]

Alas with MailboxProcessor this seems less efficient. Some resource is getting exhausted in the already meager Linux CI (memory? threadpool? waithandles? I have no idea) and it finally gives up.I'll try to optimize this somehow because I really like the Mailbox approach.

[T-Gro]

Failing after 79m on the Linux CI is strange, might be queue or machine specific.
I would not expect MacOS to be that MUCH different and it finished just fine in 44 minutes.

=> can be environmental flakiness

[majocha]

I got it to pass with #18527

[T-Gro]

Excellent job @majocha , I am really glad we are getting this contribution in and the compiler performance regression (since introduction of the many interfaces for numeric primitives) for especially numeric codebases can be fixed.

[majocha]

I spotted a bug in the eviction async. No big deal I'll post a fix later.