Address existing bugs in the existing CE-QUAL-WS Bathymetry Plug-in

[jrutyna]

Address the three issues identified by the developer (Yoav Bornstein) of the existing CE-QUAL-WS Bathymetry Plug-in as previously listed in the email to @jrutyna on 8/22/2023 and below:

1. I opened an issue to QGIS about Zonal Histogram. This happens when you have a DEM that has many numbers after the decimal point. As a work around the users can reduce the DEM to two numbers after the decimal point.

2. I got a report from one user, that if you have segments in different lengths, it does the calculation wrong. I have not had time to debug it yet. From first glance on the code, I think the two lists are not in the same order.

3. Error handling on incorrect headings in the polygon and line layers tables can be improved.