Fix LIKE escape type mapping with value converters (#3889)

Keep LIKE and ILIKE escape expressions independent from match and pattern type mapping so property converters cannot rewrite provider-generated escape values.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: e5b861c2-ea5b-411c-8efe-3d925d29c52e