Add Governor contracts (#2672)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

test/utils/introspection/SupportsInterface.behavior.js

@@ -50,6 +50,30 @@ const INTERFACES = {
     'getRoleMember(bytes32,uint256)',
     'getRoleMemberCount(bytes32)',
   ],
+  Governor: [
+    'name()',
+    'version()',
+    'COUNTING_MODE()',
+    'hashProposal(address[],uint256[],bytes[],bytes32)',
+    'state(uint256)',
+    'proposalSnapshot(uint256)',
+    'proposalDeadline(uint256)',
+    'votingDelay()',
+    'votingPeriod()',
+    'quorum(uint256)',
+    'getVotes(address,uint256)',
+    'hasVoted(uint256,address)',
+    'propose(address[],uint256[],bytes[],string)',
+    'execute(address[],uint256[],bytes[],bytes32)',
+    'castVote(uint256,uint8)',
+    'castVoteWithReason(uint256,uint8,string)',
+    'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
+  ],
+  GovernorTimelock: [
+    'timelock()',
+    'proposalEta(uint256)',
+    'queue(address[],uint256[],bytes[],bytes32)',
+  ],
 };
 
 const INTERFACE_IDS = {};