Implement key-of, value-of, unsealed shapes, fix various issues

[danog]

Attempts to fix #353, #337, #312, #309, #308, #304

Currently the biggest blockers are the regexes used for phpdoc parsing.
Maybe it's better to use the phpstan doc parser after all...

[danog]

Hi @romm, cleaned up the PR a bit, could you take a look?
Will kill the remaining mutants tomorrow :)

[danog]

Yeah couldn't resist doing a full cleanup&refactoring, will have to add more tests, open to feedback on the design in the meantime!

[romm]

Hi @danog, thanks for the massive work! I'll submit a review when I get some time.

I see that there are several topics covered, it would help a lot if you could cherry-pick them and open separate pull-requests for every case. 😊

[romm]

Hi @danog, this PR is on my prioritized todo-list, I started giving it a look, but the fact that several unrelated topics are handled makes it difficult to do a proper review. Also, the PR comes from an organization, preventing me from pushing changes.

Would you mind opening several PR with each topic separated? I can guess you're probably using this fork in your work projects, so I'll do my best to get them merged as soon as possible (also because these are great new features 😁).

From what I've seen, the main topics would be:

• Unsealed shaped arrays
• Unsealed shaped lists
• of<...> type
• key-of<...> type
• Interfaces in import annotations

Looking forward to added all of this to the codebase!

[romm]

Hello @danog. It's been almost a year and this PR did not move, conflicts number have been increased, and the amount of changes in this PR it too big anyway, so I'll have to close it.

Two of the features introduced here have already been added:

• Unsealed shaped array in fa8bb00
• value-of<…> in b1017ce

Feel free to open separate PRs with the remaining features if needed, I can help get them merged fast if really needed.

Thanks for the proposal!