Mirror source tree for adapter headers

[hgangwar]

Install adapter headers via DIRECTORY install.

Changes

• Defined ADAPTER_HEADERS.
• Installed headers from ADAPTER_HEADERS into their respective directories.
• Included create_field.h in examples for external-usage-example usage testing.

[hgangwar]

@jacobmerson

[jacobmerson]

We had a breif discussion offline. We are going to investigate converting our header definitions over to FILE_SETS which should maintain the structure.

https://cmake.org/cmake/help/latest/command/install.html#id5

This approach looks like it may also enable us to set up targets that check that the header files can be correctly included, which would be a nice test to include to our CI/CD testing.

https://cmake.org/cmake/help/latest/prop_tgt/VERIFY_INTERFACE_HEADER_SETS.html#prop_tgt:VERIFY_INTERFACE_HEADER_SETS