feat: agent callbacks for adk

[N3kox]

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📊 Coverage Report:

File coverage threshold (20%) satisfied:	PASS
Package coverage threshold (30%) satisfied:	PASS
Total coverage threshold (83%) satisfied:	PASS
Total test coverage: 84.6% (6909/8166)

[marwan38]

Does this PR resolve/relate to #513?
Thank you

[N3kox]

Does this PR resolve/relate to #513? Thank you

Yes, this pr, combined with further prs in eino-ext, will resolve the issues here.