Some changes to the self_test initialzation testing structure

In #3276 I'm working on initialization self_tests for a specific purpose. This is something that can be useful for other types of testing at initialization. There are also self_tests that require to be used within time-looping and can be distinguished from the initialization ones. The initialization ones can also be run in a bare-bones framework and exit early as well, to make it as efficient as possible.

Therefore, I'm planning on doing the following:

- [ ] Change the name of the testmod run_self_tests to run_init_self_tests
- [ ] Change usage of self_test, self test or self-test to self_tests consistently everywhere
- [x] Add namelist variable: for_testing_bypass_init_after_tests
- [x] Have it skip as much of the code as possible patterned after PTS_MODE where the point is a non-land point
- [ ] Enable running this mode with stub ATM
- [ ] Have this mode run without history or restart output
- [x] Have it exit as early as possible in initialization