to_typemod(type_name) information function

Hi,

I need to test a (user) given column type name, with one in the database
for equality. To this end, I have to do some kind of normalization (e.g.
'timestamptz(2)' to 'timestamp (2) with time zone'.)

Comparing the name alone is possible with to_regtype(type_name) or
::regtype. However, this ignores the 'typemod'.

I want to suggest a to_typemod(type_name) function which, combined with
to_regtype, would allow to decompose (and reconstruct) a type name
completely.

Best,
Sophie