tests(rpc): add filter tests (#1233)

* tests(rpc): add pending transaction filter test

* tests(rpc): add block filter and event log  test

* tests(rpc): simplify to cluster instead of comparing types

* tests(rpc): wip filter by address

* tests(rpc): add get_logs test

* fix flake8 linter

* fix flake8 linter

* add caching to readme

* add caching to readme

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>

tests/integration_tests/contracts/contracts/Greeter.sol

@@ -0,0 +1,20 @@
+pragma solidity >0.5.0;
+
+contract Greeter {
+    string public greeting;
+
+    event ChangeGreeting(address from, string value);
+
+    constructor() public {
+        greeting = "Hello";
+    }
+
+    function setGreeting(string memory _greeting) public {
+        greeting = _greeting;
+        emit ChangeGreeting(msg.sender, _greeting);
+    }
+
+    function greet() public view returns (string memory) {
+        return greeting;
+    }
+}