Fix handling of finidat with cold starts

[samsrabin]

Description of changes

This PR changes things so that:

1. Cold-start FATES runs with finidat specified will not require -ignore_warnings, and the supplied finidat will actually be obeyed.
2. Cold-start non-FATES runs will not be allowed, even with -ignore_warnings.

Specific notes

Contributors other than yourself, if any: @mvdebolskiy

CTSM Issues Fixed:

• Resolves FATES will never start from specified finidat #2856

Are answers expected to change (and if so in what way)? Yes: In cold-start FATES runs where the user was supplying finidat, that setting will actually be obeyed.

Any User Interface Changes (namelist or namelist defaults changes)? No

Does this create a need to change or add documentation? Did you do so? No

Testing performed, if any: Added checks to build-namelist_test.pl, which now pass.

[samsrabin]

@ekluzek I've converted this to a draft while I figure out what the deal is with those extra commits up top.

[samsrabin]

Okay, fixed!

[ekluzek]

@samsrabin this is great thanks for working on this. Sorry you had to work in perl, but I appreciate your working on it anyway. I have liked perl in the past and I'm still probably better in perl than in python, but I also know that ditching perl is going to be best for CTSM. But, we have to manage the current code too...

I also argue with myself below about the tests, but rested on let's bring this in as is.

Should this come to master though or b4b-dev?

[samsrabin]

Should this come to master though or b4b-dev?

@ekluzek I lean toward master, because although it doesn't change answers in our tests, it will change answers for anyone like Matvey who had tried to do cold-start FATES runs with finidat by setting -ignore_warnings. This is because their finidat setting will now actually be respected, rather than being overwritten to ' '.

[ekluzek]

Ahhh, good point master would give it more visibility. And since this makes a standard thing impossible for FATES it's good to give it more visibility and that it's fixed.

You will need to make a full ChangeLog and tag for it. But, I see your point where this warrants that even though it's small. I added it to upcoming tags and you might as well do this after b4b-dev comes in. This also brings it in sooner than the 2 week timeline for b4b-dev right now.