Add favorite queries to sessions me

[brettski]

As was done to Communities in ThatConference/that-api-events#101, add under me query favorites with two options:

• ids (returns [ID])
• sessions (returns a paged list of Community)
  One difference with sessions over the other api's is that only sessions from certain events or communities may want to be shown... This could change the current pattern used.

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• ids path added
• sessions path added