Deploy `USDCFlow.cdc` to the emulator by default

[joshuahannan]

trafficstars

Issue To Be Solved

USDCFlow.cdc for USDC is a very commonly used contract in the Flow ecosystem and developers often will want to test with it on the emulator before deploying to testnet, but it is difficult to deploy and manage.

Suggest A Solution

• Update flow-go bootstrapping to deploy FiatToken.cdc to the emulator service account and store the minter in the service account storage.
• Update documentation in various places to mention that it is deployed by default and devs can use the service account to mint USDC