[SQSERVICES-1643] Servantify brig account API 2 - GET /activate

[battermann]

https://wearezeta.atlassian.net/browse/SQSERVICES-1643

Checklist

• Add a new entry in an appropriate subdirectory of changelog.d
• Read and follow the PR guidelines

[fisx]

Suggested change

	<*> activatedFirst Schema..= (fromMaybe False <$> Schema.optFieldWithDocModifier "first" (description ?~ "Whether this is the first successful activation (i.e. account activation).") Schema.schema)
	<*> activatedFirst Schema..= (fromMaybe False <$> Schema.optFieldWithDocModifier "first" (description ?~ "Whether this is the first successful activation of this account.") Schema.schema)

(Not sure I understand, though. How often can one account be activated successfully?)

[battermann]

This is from the original swagger documentation. IMO it should not be changed in this PR. Also it is not obvious to me either how this should be phrased correctly.

[fisx]

(functionNameH traditionally means "functionName, but there is a servant handler with that name, and this is just the wrapper with the wai-route plumbing in it; will be removed once we switch to servant". So it's probably/usually a good idea to merge the two, but yes, in this case I'm not sure how to do that off the top of my head.)