[FLINK-36577] Add compatibility check for FlinkStateSnapshot

[mateczagany]

What is the purpose of the change

This adds a compatibility checks for the FlinkStateSnapshot CRD which will run the class CrdCompatibilityChecker.

Brief change log

• Add a new execution next to the existing CRD checks for FlinkStateSnapshot which ensures backward compatibility with the CRD released in version 1.10.0
• Add new unit test to ensure FlinkStateSnapshot ignores unknown fields

Verifying this change

• Changed one of the enum values of FlinkStateSnapshot locally and verified that it fails the test.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changes to the CustomResourceDescriptors: no
• Core observer or reconciler logic that is regularly executed: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? no

[kumar-mallikarjuna]

Did one pass and ran the UT locally. LGTM!