Draft: ConfigureLog: Add structured logging of checks during configure step

Start implementing a "configure log". This uses YAML for a balance of machine- and human-readability and records details of certain events (currently, try_compile and try_run) in a structured format.

This is an early implementation that will likely be improved as time goes on with the addition of more fields and more events.

Tests and documentation are included.

Issue: #23200 (closed)