Safe creation transaction details

[lukasschor]

We want to display additional information about the Safe creation transaction:

• Creation date/time
• Tx hash of Safe creation transaction
• Initiator of Safe creation

We need an endpoint that provides this information for a given Safe address

Related to 5afe/safe-react#554

[rmeissner]

This can be a separate endpoint for now

[Uxio0]

Endpoint proposal

URL

GET /api/v1/safes/<address>/creation/

Response

{
  created: "<iso 8601 datetime>",
  transactionHash: "<keccak-hash>",
  creator: "<checksummed-address>"
}