Fix module path in JDK 24 and older

[Til7701]

This PR removes the SPI entries for ValueExtractors, since they are optional dependencies and there is a bug that was fixed in JDK 25 (https://bugs.openjdk.org/browse/JDK-8347915).

Changes:

• Updated Maven Wrapper with mvn wrapper:wrapper since I had some problems with it. I do not know what the problem was, but it was fixed by updating.
• Updated module-info as explained above
• Added integration tests run by the maven invoker plugin
• The tests are only run when building with the integration-test Maven profile
• Added the following tests:
  • jakarta-jlink
    • Tests basic usage
    • Instantiates a JsonNullableJakartaValueExtractor
    • Is built using JLink
    • Runs the application by calling the script created by JLink
  • jakarta-modulepath
    • Tests basic usage
    • Instantiates a JsonNullableJakartaValueExtractor
    • Runs the application using --module-path
  • jakarta-classpath
    • Tests basic usage
    • Instantiates a JsonNullableJakartaValueExtractor
    • Runs the application using --class-path
    • Tries loading a JsonNullableJakartaValueExtractor via the ServiceLoader

closes #100