[FEA]: Implement ST_IsSimple and ST_IsValid for LineStrings and Polygons

[thomcom]

Is this a new feature, an improvement, or a change to existing functionality?

New Feature

How would you describe the priority of this feature request

Medium

Please provide a clear description of problem you would like to solve.

Currently the behavior of binary predicates in cuSpatial is undefined on degenerate geometries. OGC specifies simple ways of defining if a geometry is degenerate with ST_IsSimple and ST_IsValid, which are unary predicates that return True for geometries that do not have particular characteristics such as repeated points and self-crossing for IsSimple, and a few other more complex rules for Polygons and MultiPolygons in ST_IsValid. I think these rules would be fairly straight forward to implement and would allow users of cuSpatial to remove invalid geometries from their datasets with better performance.

Describe any alternatives you have considered

No response

Additional context

See https://postgis.net/docs/using_postgis_dbmanagement.html#OGC_Validity