Integrate the nft-server with the signature server

[LautaroPetaccio]

To complete this task do the following:

• Create the swaps module.
• Add a new source to the NFT module to get NFTs and orders from the swaps.
  • Get the swaps from the signature server and create the orders and NFTs using the information from the graph. Take into consideration the NFT metadata filters.
• Add a new source to the Orders module to get Orders from the swaps.
  • Get the swaps from the signature server taking into consideration the Order filters. Convert the swaps to orders.
• Add a new source to the Bids module to get Bids from the swaps.
  • Get the swaps from the signature server taking into consideration the Bids filters (the same as order). Convert the swaps to bids.