Remove code associated with custom notifications

[jleach]

Custom notifications was added to allow teams to add notifications as needed. This behaviour was used by the BC Wallet for inserting a call-to-action to get a Person Credential. This functionality is no longer needed as we add this by creating our own HomeHeaderView override.

This change should be brought up with the community and if it is not used by any teams the dead code should be removed.

[MosCD3]

Can you give a high level view of the alternative?
Scan QR --> Connection screen --> Offer/Request
What are you thinking of