[WIP][FLINK-37406] Add support for structured YAML config in FlinkDeployment CRD

[csviri]

What is the purpose of the change

This change introduces config field for FlinkDeployment and FlinkSessionJob as an alternative to flinkConfiguration. While flinkConfiguration accepts string key-value pairs, the new field accepts arbitrary yaml input, as defined in flink configuration documentation.

While this change allows adding values to both flinkConfiguration and config, if there is a value with same key the one from config will take precedence. However, it is the users resposibility to make sure that there are no overlapping keys, thus keys with deprecated names and with actual key names, in that case behavior is not deterministic.

TODO: Flip

Brief change log

• adds config to CRD
• backfills flinkConfiguration from config

Verifying this change

TODO describe tests

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: yes
• Core observer or reconciler logic that is regularly executed: yes

Documentation

• Does this pull request introduce a new feature? yes
• If yes, how is the feature documented? docs and JavaDocs (TODO)