feat(cql2-text): parse the A_* array predicates

[C1-BA-B1-F3]

Fixes #160.

A_CONTAINS(arrayattr, ('a', 'b', 'c')) raised
Unexpected token Token('COMMA', ','): the cql2-text grammar had no array
literal and no A_* predicate, so the call fell through to the generic
func rule (attribute "(" expression ("," expression)* ")") and died on the
comma — a parenthesized list is not an expression.

cql2-json already parses the same filter, and cql2.ARRAY_PREDICATES_MAP
already carries the mapping, so the gap was only in the text parser:

• add an array rule — a parenthesized list — reachable only from the array
  predicate, so its parentheses cannot be confused with a parenthesized
  expression elsewhere;
• add the A_EQUALS / A_CONTAINS / A_CONTAINEDBY / A_OVERLAPS
  keywords, case-insensitive like the S_* ones;
• add a transformer method that reuses ARRAY_PREDICATES_MAP, so both
  parsers produce the same AST.

Tests

8 cases added to tests/parsers/cql2_text/test_parser.py: the issue's exact
reproduction, all four operators, a single-element array, lowercase input, and
an array predicate inside an AND condition.

• On the pre-fix code all 8 fail; after the fix the module is 56/56.
• Full suite with the test extra (excluding the modules that need a live
  Elasticsearch/OpenSearch/Solr or GDAL): 324 passed / 62 skipped / 37
  errors, against a 316 / 62 / 37 baseline on main — the delta is
  exactly the 8 new tests; the 37 errors are the network-backed backend
  suites and are unrelated.
• ruff / ruff format clean; mypy reports the same pre-existing
  values.py errors as main.

The grammar's only reported conflict is the pre-existing
Shift/Reduce conflict for terminal RPAR ... <literal : bbox>; the new rules
add none, because the A_* and S_* keyword terminals disambiguate the two
spatial_predicate alternatives before any ( is read.

[C1-BA-B1-F3]

Heads-up for the maintainer: #161 (open since 2026-08-02, "Add CQL2 array predicates, cql-json ne support, and parser validation") also implements the cql2-text A_* predicates for #160, so this PR overlaps with it.

Differences, so you can pick whichever you prefer:

• This PR is scoped to A_CONTAINS with cql2_text throws error #160 only: the array rule + the four A_* keywords in cql2_text, plus 8 parser tests. It also passes ARRAY_PREDICATES_MAP through unchanged, so both parsers produce the same AST.
• Add CQL2 array predicates, cql-json \ e\ support, and parser validation #161 fixes A_CONTAINS with cql2_text throws error #160 together with cql2 does not accept single character attribute names #144 (single-character attributes), cql-json COMPARISON_MAP does not contain <> #19 (cql-json ne) and Invalid cql-json and expression is parsed into "wrong" ast #47 (cql-json validation), and touches CHANGELOG.md.

Happy to close this one if you would rather take #161 — just say so.