Backport 45942 to dev16.7. Include information why symbol key resolution has failed to help with debugging

[CyrusNajmabadi]

This PR originally went into master as #45942. We would like to pull it into 16.7 to get reports from teh wild as to what's possibly going on.

Needs QB approval.

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We've been getting a few crashes with OOP where symbol keys fail to resolve to/from the oop/host side. Previously, one thing that caused this was an inability tou roundtrip some error symbols. However, that issue was fixed and we're still seeing some sporatic failures.

This PR updates symbolkeys to report back a detailed reasoning on why they failed so that we can get that information in teh dump and potentially determine any commonality between the failures (i.e. maybe it's something to do with certain types of symbols).

This does not get rid of any issues, but only seeks to include more information to make future investigations more fruitful.

[ghost]

Auto-approval

[JoeRobich]

@CyrusNajmabadi This PR has some consistent integration test failures that did not pass on re-run. I see the same set of tests that were failing in master plus some additional ones. Which is interesting because we had not been seeing those integration test failures in the 16.7 branch yet. You should be able to merge the commit from the Skip Test PR into your branch (https://github.com/dotnet/roslyn/pull/46028/commits) without pulling anything additional along.

[JoeRobich]

@CyrusNajmabadi Created validation PR. If manual build validation or automatic succeed, then we can override the checks and merge. https://devdiv.visualstudio.com/DevDiv/_git/VS/pullrequest/262302

[JoeRobich]

PR Validation build passed and VAL build seems to be working fine. Integration failures seems to be an Editor issue in the version of VS on the VMs. This bug is fixed in the latest previews. Merging.