remote/client: let -p restrict env-wide acquire/release

[Sanjays2402]

Description

Since acquire/release started operating on all RemotePlaces in the environment config, passing both -c env.yaml and -p NAME silently ignored -p and acquired every place in the env — contending with other users and CI jobs that historically used that combination to manage one device at a time.

An explicitly requested place (-p/--place, LG_PLACE, or the legacy PLACE variable) now restricts acquire/release to that single place. Without one, the env-wide behaviour is unchanged.

Checklist

• Documentation for the feature
• Tests for the feature
• The arguments and description in doc/configuration.rst have been updated
• Add a section on how to use the feature to doc/usage.rst
• Add a section on how to use the feature to doc/development.rst
• PR has been tested
• Man pages have been regenerated

Tested locally: the new test_place_acquire_with_env_and_place fails on master (both places acquired) and passes with the fix; test_place_acquire, test_place_acquire_multiple and test_place_acquire_enforce still pass.

Fixes #1868

[Emantor]

I don't think we want to support this case. Environment files describe the complete testing environment, if only a subset of places is required for the test run, this should be done in a new separate environment file.

[Sanjays2402]

Fair enough, that's a reasonable line to hold. I read -p as already being a filter in the client, so extending it to acquire/release felt consistent, but if environment files are meant to describe the complete environment then a separate file is the cleaner answer.

Happy to close this. #1942 is unrelated and stands on its own.