fix(gwe-est): add support for energy decay in the solid phase

[emorway-usgs]

Support for specifying energy decay in the solid phase was missing despite it being described in the Supplemental Technical Information document. The best I can figure is that during development it was initially skipped over with the intention of coming back to it - but then was forgotten about.

• Replaced section above with description of pull request
• Addresses issue Missing zero-order decay for the solid phase in GWE #2142
• Functionality should have been included with pull request feat(GWE): Introduce Groundwater Energy Transport #1493
• Added new test or modified an existing test
• Ran ruff on new and modified python scripts in .doc, autotests, doc, distribution, pymake, and utils subdirectories.
• Formatted new and modified Fortran source files with fprettify
• Updated definition files
• Updated develop.tex with a plain-language description of the bug fix, change, feature; required for changes that may affect users

[aprovost-usgs]

just some minor comments for your consideration

[langevin-usgs]

Looks good to me, only 2 suggestions to consider.

1. Would seem nice to use enumerations for idcy and idcysrc.
2. Should we rename "water" to "aqueous" to be consistent elsewhere?

[aprovost-usgs]

@langevin-usgs I like your suggestion to be consistent, but the situation is a little muddy for me with respect to "aqueous" vs "water". In GWT, aqueous is used throughout. That makes sense because it's concerned with dissolved species -- "solutions" -- and "aqueous" is a common descriptor for that. But in GWE we're dealing with thermal energy. If it was just pure water being heated and cooled, "aqueous" would seem out of place. But in general it can be an aqueous solution that's being heat and cooled, so referring to it as the "aqueous phase" makes sense from that standpoint. That said, it seems to put a lot of (too much?) emphasis on the composition of the water. Another consideration is that we've already gone down the "water" path with properties in GWE, like DENSITY_WATER and HEAT_CAPACITY_WATER. That's a lot of hand wringing over a small point but just wanted to offer those perspectives

[langevin-usgs]

@langevin-usgs I like your suggestion to be consistent, but the situation is a little muddy for me with respect to "aqueous" vs "water". In GWT, aqueous is used throughout. That makes sense because it's concerned with dissolved species -- "solutions" -- and "aqueous" is a common descriptor for that. But in GWE we're dealing with thermal energy. If it was just pure water being heated and cooled, "aqueous" would seem out of place. But in general it can be an aqueous solution that's being heat and cooled, so referring to it as the "aqueous phase" makes sense from that standpoint. That said, it seems to put a lot of (too much?) emphasis on the composition of the water. Another consideration is that we've already gone down the "water" path with properties in GWE, like DENSITY_WATER and HEAT_CAPACITY_WATER. That's a lot of hand wringing over a small point but just wanted to offer those perspectives

Okay, sounds good. Just wanted to make sure we weren't missing an opportunity to be consistent. Based on your comment and seeing that "aqueous" is often used in the context of water as a solvent, it might be best to defer this for now and maybe think on how to come up with clear terminology.