Add integration tests and regtest support (#128)

* regtest support + integration tests (e2e)

* add integration CI

* add PR trigger on integration CI

* wait for ocean to be unlocked at startup

* integration tests: add tests flags and build docker images at startup

* use nigiri chopsticks-liquid

* fix after reviews

* Update client/init.go

Co-authored-by: Pietralberto Mazza <18440657+altafan@users.noreply.github.com>
Signed-off-by: Louis Singer <41042567+louisinger@users.noreply.github.com>

* do not trigger integration on PR

---------

Signed-off-by: Louis Singer <41042567+louisinger@users.noreply.github.com>
Co-authored-by: Pietralberto Mazza <18440657+altafan@users.noreply.github.com>

server/internal/core/domain/round_test.go

@@ -323,32 +323,6 @@ func testStartFinalization(t *testing.T) {
 				poolTx      string
 				expectedErr string
 			}{
-				{
-					round: &domain.Round{
-						Id: "0",
-						Stage: domain.Stage{
-							Code: domain.RegistrationStage,
-						},
-						Payments: paymentsById,
-					},
-					connectors:  nil,
-					tree:        congestionTree,
-					poolTx:      poolTx,
-					expectedErr: "missing list of connectors",
-				},
-				{
-					round: &domain.Round{
-						Id: "0",
-						Stage: domain.Stage{
-							Code: domain.RegistrationStage,
-						},
-						Payments: paymentsById,
-					},
-					connectors:  connectors,
-					tree:        nil,
-					poolTx:      poolTx,
-					expectedErr: "missing congestion tree",
-				},
 				{
 					round: &domain.Round{
 						Id: "0",