Update stream definitions for new coupler history file format

[olyson]

Description of changes

Modify stream_definition_datm.xml to generate a streams file (datm.streams.xml) with the new coupler history file format.

Specific notes

Changes to accommodate new coupler history file names.
Change offset for solar stream from 2700 to -900 to accommodate changes due to time stamps.
These changes work in conjunction with CDEPS PR #224 and CDEPS PR #222 .
Note that I did not change the file names for ndep, or remove that stream. Presumably, that stream will be removed at some point due to CAM now always sending ndep.

Contributors other than yourself, if any: @billsacks

CDEPS Issues Fixed (include github issue #): N/A

Are there dependencies on other component PRs (if so list): No

Are changes expected to change answers (bfb, different to roundoff, more substantial): Yes, in coupler history mode.

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

Testing performed (e.g. aux_cdeps, CESM prealpha, etc): I have conducted a pair of cases, an F-case to generate coupler history files, and an I-case to read those files, using the new file name convention, and compared the forcing output variables from clm history files between the two cases. @billsacks and I reviewed these differences and found them to be acceptable.

@billsacks has agree to review these changes and perform more standard testing.

Hashes used for testing: N/A

[billsacks]

This looks good to me - thanks a lot, @olyson ! I don't see any testing that exercises cplhist mode other than a test in CTSM's aux_clm, which we'll need to update (I'll open an issue for that) -- so I don't think there's any more testing needed right now beyond what you've already done.

I do think we'll need to follow up on the ndep stream, since I think we'll want to have datm read from the cplhist file for ndep, though that can be done in a follow-up PR, since right now CTSM wouldn't be listening to the ndep from datm anyway.