Improve Rego testing for library

[JaydipGabani]

Right now there is a Makefile and test.sh available for PSP policies to execute unit tests for Rego policies. But this seems outdated or needs to be updated.

Write global makerule to run src_test.rego for all policies to make testing rego policies easier.

[stale]

This issue/PR has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue/PR has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue/PR has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.