feat(java-generator): generalized Java class generation from remote CRDs

[manusa]

Description

Fix #4709

Generalizes the generate Java from remote URL CRD.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report
• I tested my code in Kubernetes
• I tested my code in OpenShift

[manusa]

Merging this one before #4694 since it will be easier for me to rebase the other one.

[manusa]

@andreaTP please provide your thoughts either way and I'll address them in a different PR

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

65.6% Coverage
0.0% Duplication

[andreaTP]

@manusa reviewing it now, I really like it thanks for the help!