Fix java version parsing

[elkkhan]

Current implementation of parsing the Java version assumes that all Java versions returned by System.getProperty("java.version") will be in MAJOR.MINOR.PATCH format (e.g 21.0.2), while this is incorrect.
This breaks on versions that do not follow this format - for example, JDK 21+35 returns 21.
This is causing two issues:

• Inconsistent date formats across different versions that are all > 1.6 - here
• Inconsistent User-agent header - here

This PR changes version parsing to use a versioning abstraction that is Comparable - I chose to use the existing implementation from maven-artifacts

I've tried to write some tests for this but to be honest I don't find the MessageBirdServiceImpl class very unit-testable, so I ended up not writing a unit test for this.

[elkkhan]

hi @denizkilic! can i get a review on this please?

[denizkilic]

Hi @elkkhan, thanks for the detailed description. The PR looks good to me. I will merge and prepare a new release.