ContractRegistry is not able to load deep-nested solidity files

[3Nigma]

When bundling Strato with Rollup, there is an option to recurse (contracts.recurse) which, when set to true, it should recursively load all the solidity files from all directory levels found at contracts.path.

It does not work: The generated ContractRegistry maintains a flatten <contract name>: <contract ABI> reference from all processed solidity files. This means that if there's a contract A located in a.sol and a contract A located at b/a.sol, there will be 2 entries with the same key in ContractRegistry:

{
  A: <a.sol A contract ABI>,
  A: <b/a.sol A contract ABI>
}

which is an invalid state.

The correct prop names should come close to the ones present in #33 :

{
  A: <a.sol A contract ABI>,
  b/A: <b/a.sol A contract ABI>
}

Note: The props currently don't contain the name of the solidity file itself (as present in #33 's description) . This means that if, for the above example, there were also a contract A present in b/c.sol, you would again hit the same name conflict issue. We will resolve this on a separate ticket.