Outline the default workflow configuration implementation

[psss]

[happz]

Proposed one potential solution in https://github.com/teemtee/tmt/issues/3538#issuecomment-2836372867

[happz]

The demo PR, https://github.com/teemtee/tmt/pull/3702, has been updated:

• check out how tmt can start tracking key value origin to make it exposed to profiles, which would resolve the default/not default decision making process

Done, VALUE_SOURCE variable now tells templates where the current value they inspect comes from.

• add --diff-ish option to tmt test export so we can play with the logging

Done, sort of: added new logging topic, profile, with --log-topic=profile tmt will emit diffs and decisions.

• check out whether this "changelog" could be written into an actual file

Not done, stored in the debug log for now.

• check out how tmt can expose the tmt profile name in results
• check out how tmt can expose the tmt profile name in test/phase environment
• add more usecases and examples, not limited to tests

Not done yet.

[happz]

The issue will remain open for the moment, I will add a PR with a story for the specification, and then we will close the issue. The follow-up implementation will be tracked elsewhere.