introducing wave forcing for sediment transport and tidal inlet test case

[seimurss]

Wave forcing was introduced for the radiation stresses following fragkouan/thetis_wci (Fragkou et al., 2024) and similarly, other fields, such as Hs, Ub, T, wave dir, and freq. were introduced and adapted in sediment transport model, albeit only orbital velocities are accounted for in bottom stresses computation.
Tidal inlet test case (Warner et al., 2008) was developed to test the seabed evolution in the presence of waves and tides.

[stephankramer]

This looks pretty good already!

My main feedback/questions at this moment are:

• what is the provenance of the data in the example. There are two .msh files do they have corresponding .geo files? One of these contains bathymetry data, where does that data come from? Is it interpolated from some netcdf file? Or is it based on an idealised analytical expression. The preferable option would be to just have a .geo file for the 2D geometry (and the output .msh) and either recreate the bathymetry on the fly at run-time, or if it is interpolated from some dataset that we can't commit to the repo, commit a firedrake checkpoint file with the interpolated data with clear instructions (a script) how to obtain the required data set and regenerate that checkpoint file (so we are able to redo this in the future when any of the file formats change). Then there's also a /Users/sshirinov/mac/cmcc/shyfem/cases/inlet/tideinlet3/ww3waves.nc where does that come from?
• Add a little more description at the head of the example to explain what the example consists of, what functionality it introduces, and a more complete reference: Warner et al. (2008) is ambiguous, maybe just add the doi link: https://doi.org/10.1016/j.cageo.2008.02.012
• at the end of thetis/solver2d.py there seem to be two new timeloops that look like they've been copied from the existing one - presumably with changes applied to it, but it's hard to see what the changes are. These should be integrated into the existing timeloop, with some logic as to when these required changes would apply.

Assuming these can be addressed, have another look through the diff yourself and make sure there's no changes you didn't mean to include (in particular don't include commented out code). Then if you remove the draft status, I would be happy to go through it in more detail line-by-line, with some nitty-gritty things (none of it really interesting). At a first glance I couldn't see any major issues implementation wise.