Add new Geospatial functions

Adding a list of geospatial features to be added. Used the following specification: https://portal.opengeospatial.org/files/?artifact_id=829

st_Dimension
st_GeometryType
st_IsEmpty
st_IsSimple
st_Boundary
st_Envelope
st_X
st_Y
st_StartPoint
st_EndPoint
st_Boundary
st_Boundary
st_Length
st_NumPoints
st_PointN
st_Centroid
st_PointOnSurface
st_Area
st_ExteriorRing
st_NumInteriorRings
st_InteriorRingN
st_NumGeometries
st_GeometryN
st_IsClosed
st_Length
st_Centroid
st_PointOnSurface
st_Area
st_Within
st_Relate
st_Intersection
st_Difference
st_Union
st_SymmetricDifference
st_Buffer
st_ConvexHull