Fix/test all cases for constant namescheme

[markcmiller86]

This fixes handling of constant nameschemes and adds several more test cases for them.

The critical code here is in commit 43a52d7. But I ran into several other things while creating that patch that are worth fixing here too.

• Since I was doing builds without HDF5 (didn't need it for this), I discovered some issues doing a PDB-only build and fixed those.
• I updated the documentation regarding namescheme delimiter character and constant nameschemes.
• I was doing the work on a mac and discovered some issues with running test suite on a mac involving rpath.
• I fixed some issues with CI uploading failure artifacts and RC branch regex pattern matching.

[cyrush]

Confirming patch works for with Conduit use cases

[markcmiller86]

Ok, thanks @cyrush. I put some other changes in this PR that were about fixing testing on macOS including some ASAN failures and CI artifact upload...related to the namescheme issue because I wasn't able to test and examine failures without those changes.