2261 get progenitor

[ilija-lazoroski]

What does this PR do?

Fixes part of #2261 .

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[VakarisZ]

We should probably just name the parameter 'agent'. Descendant means that it's not the progenitor, but in fact this method might get called where descendant IS the progenitor. It's pretty clear from the signature get_progenitor(self, agent) that you're getting a progenitor of an agent. IF not, then let's change the name to get_agent_progenitor

[VakarisZ]

Mainly I don't see why we can't search progenitor of an agent which is already a progenitor

[shreyamalviya]

Where is this from?

[shreyamalviya]

Suggested change

	"""
	Gets the progenitor `Agent` for the agent.
	:param agent: The Agent for which we want the progenitor
	:return: `Agent` progenitor ( an initial agent that started the exploitation chain)
	:raises RetrievalError: If an error occured while attempting to retrieve the `Agent`
	:raises UnknownRecordError: If the agent ID is not in the repository
	"""
	"""
	Gets the progenitor agent (initial agent that started the exploitation chain) for a particular agent
	:param agent: The agent whose progenitor should be retrieved
	:return: The progenitor agent
	:raises RetrievalError: If an error occurs while attempting to retrieve an agent
	:raises UnknownRecordError: If the agent ID is not in the repository
	"""