SCHISM pre/post processing integration in workflow

[janahaddad]

Goal

• Scripts designed for integration into the UFS coastal app workflow
• Uses the PySCHISM library for SCHISM model input file generation

Related

• See @mansurjisan progress initially documented in ufs-coastal DATM+SCHISM DuckNC ufs-weather-model#127
• PySCHISM visualization and other enhancements in Re-assess/update PySCHISM #8

Other potential new features to consider

• creating elev.th input file is not currently supported?