fix(sfe): fix sfe storage issue

[emorway-usgs]

Parallels the fix described for #2618. As with SFT, the storage term for SFE was not correct for standard SFR flow approach ("quasi-steady-state", meaning one steady flow solution to another that may have different flow rates and therefore a different amount of storage in each reach). Until this fix, the volume for the previous time step was calculated using the current storage flow rate, resulting in zero storage change for SFR. The SFT storage term is now calculated using the current and previous reach volumes. This change may affect existing models that use SFE.

• Replaced section above with description of pull request
• Related to pull request fix(sft): fix sft storage issue #2618
• Added new 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
• Added docstring comments to new and modified procedures
• Updated develop.toml with a plain-language description of the bug fix, change, feature; required for changes that may affect users