Some coupler variable standard names could be simplified

### Issue Type

Other (please describe below)

### Issue Description

As mentioned in the CAM-SIMA PR #402 discussion [here](https://github.com/ESCOMP/CAM-SIMA/pull/402#discussion_r2222931161), it would likely be beneficial to change the standard names of the some of the coupler variables to be closer to the "base" name, and remove the `from_coupler` and `to_coupler` suffix, as they may not be providing any beneficial disambiguation (and may make the physics itself less clear).

Please note that these changes aren't required for any current or future CAM-SIMA physics configuration, but would be beneficial to do before any [ESMStandardNames](https://github.com/ESCOMP/ESMStandardNames) dictionary update, or before we push physics schemes over to the [NCAR/ccpp-physics](https://github.com/NCAR/ccpp-physics) repo to be shared.

### Will this change answers?

No

### Will you be implementing this yourself?

Any Software Engineer can do this