proto(sql): rename table and catalog fields, drop _name suffix

Table and Catalog fields carried a redundant
_name suffix, and connection_name still used the
old "connection" term for what the API now calls
a catalog. namespace_name on Table also read as
if the namespace belonged to the table rather
than the catalog that owns it. Rename the fields
to catalog, catalog_namespace, topic, subject,
and output_schema_full_message so names match
the resource terminology. The renumbering is
safe while the v1alpha3 SQL API is unstable.

Author: r-vasquez