fix: log client-safe exceptions at ERROR instead of CRITICAL (#1193)

[ousamabenyounes]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Documented?	no
Fixed tickets	#1193
License	MIT

Problem

ErrorLoggerListener only special-cases UserError and UserWarning; every other
exception falls through to LogLevel::CRITICAL:

if ($exception instanceof UserError) { ... return; }
if ($exception instanceof UserWarning) { ... return; }

$this->log($exception, LogLevel::CRITICAL);

ArgumentsValidationException implements GraphQL\Error\ClientAware and returns true
from isClientSafe(), so it is a client fault (an invalid input), not an internal
server error. It was nonetheless logged as CRITICAL, polluting error logs for what is
routine input validation.

Fix

Add a branch, after the UserError / UserWarning checks and before the CRITICAL
fallthrough, that treats any client-safe ClientAware exception like a UserError:
log its previous cause (if any) at ERROR, and never at CRITICAL.

UserError and UserWarning (also ClientAware) keep their existing, more specific
handling because they are matched earlier. A ClientAware exception with
isClientSafe() === false still falls through to CRITICAL.

Test verification (RED → GREEN)

Two data-provider cases added to ErrorLoggerListenerTest for
ArgumentsValidationException (with and without a previous cause).

RED — on the unmodified branch (fix reverted, tests only), both cases hit the
CRITICAL fallthrough:

FAILURES!
Tests: 10, Assertions: 9, Failures: 2, Risky: 1.
(expected 'error' / no log, actual 'critical')

GREEN — with the fix:

OK (10 tests, 10 assertions)

Full suite is iso-baseline (the 5 pre-existing GraphDumpSchemaCommandTest failures on
master are unrelated and unchanged): Tests: 714, Failures: 5.