[datadogagent/finalizer] Delete dependencies of V2 agents

[davidor]

What does this PR do?

Implements a finalizer for V2 agents. The finalizer removes all the resources associated with the agent.
Before this PR, cluster roles and cluster role bindings were not being deleted.

Describe your test plan

When deleting a V2 agent, check that its associated resources are also deleted.

[github-actions]

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[codecov-commenter]

Codecov Report

Merging #576 (4be3dd2) into main (86164f0) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #576   +/-   ##
=======================================
  Coverage   58.51%   58.51%           
=======================================
  Files           3        3           
  Lines         135      135           
=======================================
  Hits           79       79           
  Misses         43       43           
  Partials       13       13           

Flag	Coverage Δ
unittests	58.51% <ø> (ø)

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[davidor]

Rebased on top of main to fix conflicts.

[celenechang]

thought about it for a while and i'm ok with this approach, feels future proof.