Keep using RO metadata after creating IMetaDataImporter for PDB reading

[hoyosjs]

This change allows the runtime to keep using the read-only view of the metadata interfaces
after the conversion of it has been requested to back calls into the classic PDB parser.
Swapping of the cached RW converted view it will be deferred until some other path (e.g.
profiler, MD emit) requests a RW view of it.

Fixes #90563

[carlossanlop]

When ready, please send an email to Tactics requesting approval. Friendly reminder that we need this merged before 4pm tomorrow Friday 20th to ensure it goes into GA.

[jkotas]

@hoyosjs We should get this into main first and let it bake there for at one or two weeks before backporting the change to servicing.

[hoyosjs]

That's the idea. I just had created this against 8 originally, so I opened the draft to get some CI coverage. Need to create the main PR. This won't go in before 8.0 releases for sure.

[carlossanlop]

@hoyosjs please target the release/8.0-staging branch. It has been created now.

[carlossanlop]

Friendly reminder: If you'd like this to be included in the December release, please merge it before Tuesday November 14th EOD (Code Complete).

[ghost]

Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.