Restrict LIKE and ILIKE to supported PostgreSQL types

[alexeichhorn]

Problem

like and ilike currently use the general comparison-value bounds, so unrelated operands compile:

Metric::attempts.like(1_i32);
Event::id.ilike(uuid::Uuid::nil());

PostgreSQL rejects the generated operators at execution time.

Expected behavior

• Restrict LIKE sources and patterns to supported text and BYTEA operands.
• Restrict ILIKE to text operands; PostgreSQL does not provide BYTEA ILIKE.
• Support required/nullable source and pattern combinations with the correct optional boolean output.
• Apply the same restrictions to columns and computed expressions.
• Add compile-fail coverage for numeric, UUID, date/time, and other unrelated types.
• Preserve &str convenience for text patterns.

Use separate marker traits if necessary because LIKE and ILIKE do not have the same PostgreSQL operand set.