refactor stream usage

[mvertens]

Description of changes

Refactorization across the data components and bug fix

streams/dshr_strdata_mod.F90

• bug fix for reading in unstructured grid data (e.g. ne16pg3) at multiple levels

datm:

• refactor datm to split out optional streams (e.g. ndep, co2, presaero, o3) into their own modules.
• refactor the other data modes to explicitly check for the stream names and ensure that required streams are indeed available.

dice:

• refactor the other data modes to explicitly check for the stream names and ensure that required streams are indeed available

docn:

• refactor the other data modes to explicitly check for the stream names and ensure that required streams are indeed available.
• remove iaf since it was a duplicate of dom

TODO: refactorization of dwav and drof is still to be completed.

Specific notes

Contributors other than yourself, if any:

CDEPS Issues Fixed:

Are there dependencies on other component PRs (if so list):

Are changes expected to change answers (bfb, different to roundoff, more substantial):

Any User Interface Changes (namelist or namelist defaults changes):

Testing performed (e.g. aux_cdeps, CESM prealpha, etc):

Hashes used for testing:

[billsacks]

I have opened a new PR - #364 - to bring in the existing changes from the noresm branch. I have then changed this PR to have a base branch of the noresm branch so it just shows diffs from that branch. @mvertens you mentioned splitting this PR into two pieces, which I didn't follow; I support doing this if it makes sense to you. Our first order of business should be merging #364 . Then we can change the base branch back to main.

[billsacks]

@mvertens - I have moved some of the bullet points from your initial description to the initial description in #364 (removing them from the description above and adding them to the description there). Can you check to confirm that I have moved the correct bullet points to that PR?

[mvertens]

@billsacks - your summary of this PR is accurate. Thank you. How do you propose we tackle working on your suggestions?