[5pt] Organize the path for model catalog csv file

[AliForghani-NOAA]

There are two issues regarding catalog file.

Current behavior

1- Currently, the tools/s3_get_models.py has two flags to manage the outputs. These are 1) -tm that specifies the directory for HEC-RAS models, and 2) -tcsv that specified the directory for catalog CSV file. Confusion (or even file misuse) can occur if the user does not intelligently select appropriate inputs for both flags.

2- Also, when running python ras2fim.py, we get a "OWP_ras_models_catalog_HUC8***.csv" in the output folder. If user does not specify -mc flag, this catalog file is copied from the one in "c:\ras2fim_data\OWP_ras_models\OWP_ras_models_catalog_HUC8***.csv". This might not be necessarily correct for the same reasons explained above-- practically, the catalog file can be located in a total different path than the HEC-RAS models.

Expected behavior

1- The `tools/s3_get_models.py' should only have a single flag for the output directory. Running the script should create below items in the output directory:

• The catalog csv file
• a sub-folder called "models" that contain all downloaded HEC-RAS models

2- If existence of catalog file is really necessary for the ras2fim run, It is safer to make the -mc flag as required and ask the user to explicitly specify its path, rather than assuming a default path for it, which might be completely unrelated to the input HEC-RAS models.