[Enhancement] rename image() → parseImageReference() and deprecate image() alias

[Denish3436]

Description

Need to update the CEL helper reference:

• Rename the table entry image() → parseImageReference()
• Add a “Deprecated: image() alias” note (to be removed in v1.15)
• Update all example snippets that call image(...) to use parseImageReference(...)

https://github.com/kyverno/kyverno/pull/12895

Slack discussion

No response

[Ayushrao1970]

/assign