fix: sync function update

[jp4g]

Should be good to go- changes:

• adds a ./docker/docker-compose.yml script that provides anvil local RPC and mongodb
  • run yarn docker up or yarn docker up -d (shut down with yarn docker down) to use
  • run yarn docker:clean to remove artifacts from containers
• adds ./docker/populate.js script which drives user enrollment & tag/ url submission through the api
  • run yarn populate to use
• set .example.env private key to anvil test private key to provide gas
• remove syncing of User
  • remove syncedToBlockchain field from User schema
• Update tags, urls to sync with current contract
  • Filters Tag/ URL documents from db to only commit tags/ urls that are not synced
  • Marks syncedWithBlockchain as true in Tag/ URL documents once synced
• syncDataToSmartContract now returns response through express and does not timeout on http

[jp4g]

uses https://github.com/State-Channel-4/contracts/pull/5