Fix PHP CALL extraction: add support for method, static, and unqualified function calls #297

[Bakul2006]

Root cause: PHP node child-type mismatch in _get_call_name.
Fix: PHP-specific handling + scoped/nullsafe node coverage + regression tests.
Addressing the issue #297 and #273

Changes
Expanded PHP call node coverage in parser call node configuration.
Added PHP-specific call-name extraction logic

[kojiromike]

Tested this PR locally against OpenEMR (4,770 files, a large PHP codebase). Results are dramatic:

Metric	main	PR #298
PHP CALLS edges	58	145,423
Total graph edges	156,005	304,632

Spot-checking the top targets shows real PHP patterns now resolve correctly — method calls (addChild, text, get, saveXML), static calls (OEGlobalsBag::getInstance), framework/test calls (assertEquals, assertSame), and OpenEMR-specific globals (sqlQuery, sqlStatement, xl, xlt).

Sample blast-radius query on sqlStatement now returns real callers with correct file paths and line numbers — e.g. C_Document.view_action at multiple sites, C_PatientFinder.search_by_FullName, etc. Pre-PR this returned nothing.

The scoped_call_expression handling that constructs Class::method targets is especially valuable — it's what makes OEGlobalsBag::getInstance (and many other singletons/factories across the codebase) participate in caller graphs. Also good catch on nullsafe_member_call_expression ($obj?->method()) — that's increasingly common in modern PHP.

One small observation: the _normalize_php_name helper is currently defined as a closure inside _get_call_name. If this pattern repeats for other languages (e.g. Perl/Ruby also have sigil-prefixed names in some grammars), it might be worth promoting to a module-level helper. Just a thought for a follow-up.

LGTM from an end-user perspective. Thanks for the fast turnaround.