Add option to list modules in export codegen

[benber86]

When trying to move from importing __interface__ to explicit imports, if a contract relies on a lot of module, it can be unclear what function is coming from an underlying module and what is defined in the contract. This PR adds an argument to codegen exports so that if an exported function is coming from a module, the module's name will be displayed as a comment next to it.

For instance in the scrvusd_oracle contract in the tests:

> natrix codegen exports tests/contracts/scrvusd_oracle/scrvusd_oracle.vy --display-modules

# NOTE: Always double-check the generated exports
exports: (
    scrvusd_oracle.max_acceleration,
    scrvusd_oracle.owner,  # ownable
    scrvusd_oracle.price_v0,
    scrvusd_oracle.price_v1,
    scrvusd_oracle.prover,
    scrvusd_oracle.raw_price,
    scrvusd_oracle.renounce_ownership,  # ownable
    scrvusd_oracle.set_max_acceleration,
    scrvusd_oracle.set_prover,
    scrvusd_oracle.transfer_ownership,  # ownable
    scrvusd_oracle.update_price,
    scrvusd_oracle.version
)