fix #4931: using coarse locking to prevent odd concurrent behavior

[shawkins]

Description

Switches all of the operation methods to be synchronized to ensure full consistency - beyond the map of resources we also hold some mutable crd state in CustomResourceDefinitionProcessor, which this will cover as well. This could also easily be implemented in CrudDispatcher, but that requires another release of the mock webserver.

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

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

74.6% Coverage
0.0% Duplication