fix(stack/contracts-manager): ensure custom abiDefinition is set properly if provided

Turns out that 17cec1b has never worked as intended.
Custom provided `abiDefinition` values have been simply ignored. Embark always used the
`abiDefnition` that resulted from the Smart Contract compilation.

Author: 0x-r4bbit

packages/stack/contracts-manager/src/index.js

@@ -325,7 +325,7 @@ export default class ContractsManager {
           contract.swarmHash = compiledContract.swarmHash;
           contract.gasEstimates = compiledContract.gasEstimates;
           contract.functionHashes = compiledContract.functionHashes;
-          contract.abiDefinition = compiledContract.abiDefinition;
+          contract.abiDefinition = contractConfig?.abiDefinition ?? compiledContract.abiDefinition;
           contract.filename = compiledContract.filename;
           contract.originalFilename = compiledContract.originalFilename || ("contracts/" + contract.filename);
           contract.path = dappPath(contract.originalFilename);