Add uninitialised variables check to CI build

[aidanheerdegen]

Adding in the initialised variable checks to CI build.

Should have added this in #349

[aidanheerdegen]

@russfiedler can you take a look and give me a sanity check before I merge?

Summary: this is a PR which adds bounds checking to the compile step. In order for this to work it requires the -Werror directive, which throws up all sorts of unrelated errors.

I started down the road of trying to fix all the old legacy code in the atmosphere code, but in the end reverted most of that and omit ESM2M, CM2M and ICCM from the --debug` build.

In the end most of the changes are superificial: just removing non-standard labels from #endif preprocessor directives.

[aidanheerdegen]

I have run a repro test (tests a 1 degree and 0.25 degree model)

https://accessdev.nci.org.au/jenkins/blue/organizations/jenkins/mom-ocean.org%2FMOM5_PR/detail/MOM5_PR/15/pipeline/

[aidanheerdegen]

Will assume silence is assent and merge

[aekiss]

Thanks for all your work on this.