feat: tx list function name fuzzy search

[He1DAr]

Implemented fuzzy search for transaction list query using the pg_trgm extension, starting with indexing the contract_call_function_name column. Future plan is to expand the index to cover more columns, improving search flexibility, e.g.:

CREATE INDEX idx_search_term_trgm
ON public.txs
USING gin (
  contract_call_function_name gin_trgm_ops,
  contract_name gin_trgm_ops
  memo gin_trgm_ops
  ....
);