Bug fixes: Add missing `handle_type_name` specializations.

[rwgk]

Description

This PR adds a number of missing handle_type_name specializations that have accumulated over time unnoticed, until work under #4888 exposed the issue. This PR is based on #4888, but omits behavior changes other than the pure bug fixes.

To prevent future accumulation of missing handle_type_name specializations, this PR adds the -DPYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION cmake option, which is OFF by default, but set to ON for some (but not all) ci.yml jobs. When ON, missing handle_type_name specializations trigger compilation errors.

The quote_cpp_type_name() function introduced in #4888 is included here, but with the implementation changed to a no-op. This pin-points where C++ type names "slip through" (and could confuse stubgen), and enables easy future experimentation similar to #4888.

Caveat: The test coverage for the handle_type_name specializations is incomplete: while the -DPYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION option ensures that no specializations are missing, some of the names could be changed without triggering unit test failures.

Suggested changelog entry:

[rwgk]

@henryiii It's past bedtime in my time zone. I'll look at the GHA results tomorrow.

Current thinking based on the hope that the GHA results look good:

• With -DPYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION=ON (default is OFF) we can be sure that we're not missing any specializations.

• But full test coverage for all specializations is still missing. I believe it's at least a couple hours of leg work to achieve full coverage. Do we really need it? The specializations are pretty trivial: are code reviews sufficient?

[rwgk]

@henryiii The PR description is complete now, with "Caveat" regarding unit test coverage.

I believe it's a minor caveat and we should include these bug fixes in the release as is. Or I could work on making the unit test coverage complete over the weekend, and we release next week.