[FLINK-37229] Add/record DELETING/DELETED lifecycle states

[gyfora]

What is the purpose of the change

The current lifecycle states and events don't properly track resources that are being deleted. Long / stuck delete operations do not result in intuitive states.

This changes introduces 2 new states, deleting and deleted to track the deletion process. Once a resource is marked for deletion it will always return DELETING until the deletion success which will return a one time DELETED state (but this will only be seen as an event as the deleted resource won't be in kubernetes anymore)

Brief change log

• Introduce new states and update reconciler logic
• tests

Verifying this change

Tests, and validation in various envs

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: no

Documentation

• Does this pull request introduce a new feature? yes
• If yes, how is the feature documented? JavaDocs