x/evm: StateBD tests (#407)

* draft state_transition

* working test

* keeper test

* statedb rewrite

* fix tests

* add keeper statedb test

* minor changes

* x/evm: StateBD tests

* try fix

* fix stateObject.setState

* Update x/evm/types/state_object.go

* update stateObject.setState

* uncomment test

* increase coverage

* fix test-import

* update rpc tests

Co-authored-by: Justin Thompson <justin.thompson12@hotmail.com>
Co-authored-by: noot <elizabethjbinks@gmail.com>

tests/rpc_test.go

@@ -532,6 +532,7 @@ func TestEth_GetFilterChanges_NoTopics(t *testing.T) {
 
 	// instantiate new filter
 	rpcRes = call(t, "eth_newFilter", param)
+	require.Nil(t, rpcRes.Error)
 	var ID hexutil.Bytes
 	err = json.Unmarshal(rpcRes.Result, &ID)
 	require.NoError(t, err)