0.28.0

Breaking changes

• Use TriggerEventExpr instead of plain TriggerEvent (d5ca16d)
• Extract timeKw from TriggerEvent (9e0d309)
• Extract TriggerTarget from TriggerEvent (d37a94b)
• Rename TriggerCondition to WhenClause (7cd0758)
• Replace CreateTriggerStmt.eachKw and .when fields with .clauses (56a69b4)
• Don't parse unicode escapes in PostgreSQL unicode strings and identifiers (f715a15)

Improved PostgreSQL support

• Support FILTER() in aggregate functions
• Revert an accidental change to row_constructor syntax
• Support PostgreSQL TRIGGER syntax:
  • Support CREATE TRIGGER
  • Support REFERENCING clause in TRIGGER
  • Support trigger timing clause
  • Support trigger FROM clause
  • Support FOR EACH clause
  • Support TRUNCATE event
• Support ALTER PROCEDURE & ALTER FUNCTION
• Support newline-separated strings, E'strings' and U&'strings'
• Support UESCAPE in unicode strings & identifiers
• Support underscores in number literals
• Update keywords list for PostgreSQL 16 (add SYSTEM_USER)