Support advanced symsrv paths

[DrChat]

Documentation: https://learn.microsoft.com/en-us/windows-hardware/drivers/debugger/advanced-symsrv-use

Main things to support:

• Cache chaining: SRV*C:\Cache1*C:\Cache2*https://msdl.microsoft.com/download/symbols
• Default local cache: SRV**https://msdl.microsoft.com/download/symbols (Default local cache path (short-form server string) #15)
• In-memory only: SRV*https://msdl.microsoft.com/download/symbols

[mstange]

The symsrv crate has parsing code for this syntax, if you're curious.

[DrChat]

Yeah - I had actually opened this ticket after seeing your repository had it implemented correctly.
Tbh I would prefer to use your repository instead of maintaining our divergent copy, but one requirement we have is that PDBs are downloaded to a local cache directory so that the library returns file paths instead of in-memory blobs.