perf(UZF): add deprecation warning for SIMULATE_GWSEEP

[emorway-usgs]

• Relates to Does UZT route mass from GWSEEP? #915 and fix(tsp-apt): pair the user-specified concentration for finf with rej. infiltration #1719
• It is not recommended to use SIMULATE_GWSEEP because of the potential for errors with MVT and MVE
• A better approach is to use the AUXDEPTHNAME option available within the DRN package. An example showing how to use this option with a comparison to groundwater seepage calculated by the UZF package is provided in MODFLOW 6 examples GitHub repository. The example is titled "Drain Package Drainage Discharge Scaling Option Problem 1"
• As of right now, only a deprecation warning is introduced. The functionality still remains for the time being with a warning message to the user.
• fprettify

[langevin-usgs]

nice