Implement feature 5973 - add SARIF output format

[llaville]

As it is my first PR on this project, hope I don't forget any steps.

• make cs OK
• make tests OK

My first remark:

• As I don't found any API / constant that give current PHPStan version, I've hardcoded it in SarifErrorFormatter and unit tests.

Waiting for your feedbacks

[llaville]

make phpstan has an error (even on master branch)

php bin/phpstan clear-result-cache -q && php -d memory_limit=768M bin/phpstan
Note: Using configuration file /shared/backups/github/my-phpstan-src/phpstan.neon.dist.
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 ------ ----------------------------------------------------------------------------------------------------------
  Line   src/Rules/RuleErrorBuilder.php
 ------ ----------------------------------------------------------------------------------------------------------
         Ignored error pattern #^Variable property access on PHPStan\\Rules\\RuleError\.$# in path
         /shared/backups/github/my-phpstan-src/src/Rules/RuleErrorBuilder.php was not matched in reported errors.
  149    Variable property access on object.
  152    Method PHPStan\Rules\RuleErrorBuilder::build() should return PHPStan\Rules\RuleError but returns object.
 ------ ----------------------------------------------------------------------------------------------------------


 [ERROR] Found 3 errors


make: *** [Makefile:59: phpstan] Error 1

[ondrejmirtes]

And please fix the Windows failures :)

[ondrejmirtes]

This should be in config.neon.

[ondrejmirtes]

Please try to do this without a dependency. It's just encoding a simple JSON after all.

[ondrejmirtes]

The version can be obtained like this:

phpstan-src/bin/phpstan

Lines 109 to 114 in 1789915

	$version = 'Version unknown';
	try {
	$version = \Jean85\PrettyVersions::getVersion('phpstan/phpstan')->getPrettyVersion() ?: $version;
	} catch (\OutOfBoundsException $e) {
	}

[ondrejmirtes]

Feel free to open a new PR if you decide to finish this, thanks :)