Deprecate --evidence option

[alfinkel]

Overview

--evidence does not reflect what it actually does. It might be good to deprecate it and replace it with something more meaningful like --locker-mode. We also could include --locker-path to set the root path for the locker instead of using tmpdir.

Approach

• Be backward compatible so a warning can be shown for a while.
• Retire --evidence during a major release.

Security and Privacy

No impact

Test Plan

TBD