Adds regex-parser library

Adds the `yoeunes/regex-parser` library as a dependency.

This library will be used for advanced regular expression
validation and analysis within the application.

Also updates the .gitignore to ignore vendor directories
within the `src` directory, and adds `composer.lock` to it.

.gitignore

@@ -17,3 +17,6 @@
 /npm-debug.log
 
 /tests/Symfony/Fixtures/project/public/vendor/
+
+src/**/vendor/
+src/**/composer.lock