Add missing tagMap & typeMap in pyasn1 encoder/decoder

[Avasam]

Required for #9470
These are meant to be exported (and are actually used) as a helper mapping of types for specific encoder/decoder

To avoid very large unions and complex overloads, I've kept only the base types.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[AlexWaygood]

Oh, I guess stubtest didn't flag these as missing because of the fact that the runtime defines __all__, and these are omitted from __all__ at runtime. But if our ldap3 stubs need them, that's a good enough reason to include them here!

[AlexWaygood]

Actually, on second thought, I'm really not sure we should add these symbols to the stub. They're all marked with comments in the source code saying that they're deprecated aliases, and none of them are included in __all__. I think there's an alternative solution to the issue with the ldap3 stubs -- see my comments here: #9470 (comment)