Issue:

Our WKT parser doesn't allow multipoint provided in this form: MULTIPOINT((0 0), (1 1)),
but this format was defined by OGC as standard WKT format for multipoints.

Fix:

Allow above format, and also allow the old format: MULTIPOINT(0 0, 1 1),
but do not allow the mixture of both formats in the same multipoint geometry.
And at the same time, output multipoint WKT in OGC standard format.