$formatNumber: invalid picture patterns leak raw java.lang.IllegalArgumentException / miss validation (jsonata 2.2.1)

[wnm3]

Surfaced while comparing JSONata4Java against the jsonata-js 2.2.1 test corpus during the Jackson 3 migration (#430 / PR #431). These are pre-existing functional-compatibility gaps vs the reference implementation (try.jsonata.org 2.2.1), not regressions introduced by the migration.

$formatNumber mishandles several invalid/edge picture strings — either leaking a raw java.lang.IllegalArgumentException (rather than a JSONata EvaluateException) or producing output the reference rejects.

Expression	JSONata4Java	jsonata.org 2.2.1
$formatNumber(42, "%%")	raw java.lang.IllegalArgumentException: Too many percent/per mille characters	error (well-formed JSONata error)
$formatNumber(42, "‰‰")	raw java.lang.IllegalArgumentException: Too many percent/per mille characters	error
$formatNumber(42, "%‰")	raw java.lang.IllegalArgumentException: Too many percent/per mille characters	error
$formatNumber(42, "---")	returns "---42"	error (invalid picture)

Expected: these should raise a proper JSONata EvaluateException (D3080-class picture-string error) rather than leaking an internal Java exception or silently accepting an invalid picture.

Reference: jsonata-js 2.2.1.