[CRISvsGAME]

Fix formatting of TRIGGER when used as a function return type.

By default, pgFormatter uppercases SQL keywords and lowercases data types. However, RETURNS TRIGGER was formatted using keyword case even though trigger is a PostgreSQL pseudo-type.

The fix recognizes TRIGGER as a type in the RETURNS context and applies the configured type case without affecting keyword formatting elsewhere, such as CREATE TRIGGER.

Regression coverage includes:

• Default lowercase type formatting for RETURNS trigger
• Preserving mixed-case tRiGgEr with --type-case 0
• Preserving keyword formatting for CREATE TRIGGER
• Updated existing regression fixtures to reflect the corrected output

Validation:

• prove -Ilib t/*.t — 97 tests passed
• perl t/regress_test.pl — passed