Convert unhandled PHPT exceptions to skipped test result

[epdenouden]

Fixes #3011 which is very much like #3490

Verification

You can see the exception handling at work when you manually run the new end-to-end test:

phpunit --testdox tests/_files/phpt-unsupported-section.phpt

[...]
PHPUnit\Runner\PhptTestCase
 → tests/_files/phpt-unsupported-section.phpt [0.00 ms]
   │
   │ PHPUnit does not support PHPT GET sections
   │ 
[...]

Changes

• PHPT parsing exceptions now result in a properly skipped test instead of stopping PHPUnit
• update existing PhptTestCase unit tests
• add new end-to-end test with unsupported PHPT --SECTION--

Note

The improved exception handling is designed to prevent PHPUnit from crashing out during a run, which works in both the 7.x and 8.x major versions. Version 8 additionally has the improved Testdox and error output which provides much more detailed code locations.

[codecov]

Codecov Report

Merging #3529 into 7.5 will increase coverage by 0.02%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##                7.5    #3529      +/-   ##
============================================
+ Coverage     83.41%   83.44%   +0.02%     
- Complexity     3627     3628       +1     
============================================
  Files           143      143              
  Lines          9662     9667       +5     
============================================
+ Hits           8060     8067       +7     
+ Misses         1602     1600       -2

Impacted Files	Coverage Δ	Complexity Δ
src/Runner/PhptTestCase.php	81.46% <100%> (+1.28%)	84 <0> (+1)	⬆️

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