Goal: 
As per discussion during OSPRH-19177 PR code review, we found out that we should make some changes that makes unit-test stuff more clear.
1. We decided that we should update the Makefile file content by replacing the `test-api` name with `unit-test` since it gives us more clarity.
2. Currently, Makefile `test-api` just looks for unit test in ironic-operators `api` directory for the unit tests which is not right we want it to search for all the ironic-operators directories for unit test and make sure it exclude the `test` folder since it has ginko tests in it and we don't want to run them.
3.  Also we want out unit-test to run after every commit so we should add them in the Ironic operator's pre-commit hook.

Acceptance Criteria:

• Replace `test-api` -> `unit-test` in the Makefile.
• Makefile's `unit-test` should search for unit tests in all the ironic-operator's directories excluding test directory.
• Add  Makefile's `unit-test` to the Ironic-Operator's pre-commit hook.