There are different types (variants) of UUIDs defined.
Especially variants 3 and 5 are name based variants (rfc4122).

The way we create our UUIDs in nm_utils_uuid_generate_from_string()
however does not create them according to RFC and does not set
the flags to indicate the variant.

Modify the signature of nm_utils_uuid_generate_from_string() to accept
a "uuid_type" argument, so that we later can add other algorithms without
breaking API.