Treat uninitialized property as not existing

[batyrmastyr]

Q	A
Is bugfix?	✔️
New feature?	❌
Breaks BC?	❌

Treat uninitialized property as null to align with ArrayDataSet and inexisting properties handling.

$parser = new ObjectParser(new class () {
    public int $a = 4;
    public int $uninitialized;
});

$this->assertNull($parser->getPropertyValue('not-existing')); // null 
$this->assertSame(4, $parser->getPropertyValue('a'));   // 4
$this->assertNull($parser->getPropertyValue('uninitialized')); // exception in main branch

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.20%. Comparing base (fe63447) to head (3ada8cd).
⚠️ Report is 90 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #783      +/-   ##
============================================
+ Coverage     94.40%   96.20%   +1.80%     
- Complexity      953     1044      +91     
============================================
  Files           108      122      +14     
  Lines          3018     3292     +274     
============================================
+ Hits           2849     3167     +318     
+ Misses          169      125      -44     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[vjik]

Thank you, @batyrmastyr !