fix: quote username in views/mview test helper for dotted local roles

Same dot-username bug as 504775de8 / 9b29bc203 but in a different shape:
view_test_data.json query strings are Python expressions interpolating
server['username'] into ALTER TABLE ... OWNER TO and GRANT ... TO
clauses. views/tests/utils.py:create_view evaluates these expressions,
producing SQL with an unquoted identifier. A local PG role with a dot
(e.g. 'ashesh.vashi') was rejected with 'syntax error at or near "."'.

Substitute server['username'] with Driver.qtIdent(None, server['username'])
in the query template before evaluating, so the resulting SQL contains
the properly-quoted identifier. The substitution covers every
occurrence in the template (some queries have OWNER TO and GRANT TO in
the same string).

Accounts for the remaining 72 'syntax error at or near "."' cases that
504775de8 + 9b29bc203 did not reach.