feat(e2e-testing): maintnotifications e2e and refactor (#3526)

* e2e wip

* cleanup

* remove unused fault injector mock

* errChan in test

* remove log messages tests

* cleanup log messages

* s/hitless/maintnotifications/

* fix moving when none

* better logs

* test with second client after action has started

* Fixes

Signed-off-by: Elena Kolevska <elena@kolevska.com>

* Test fix

Signed-off-by: Elena Kolevska <elena@kolevska.com>

* feat(e2e-test): Extended e2e tests

* imroved e2e test resiliency

---------

Signed-off-by: Elena Kolevska <elena@kolevska.com>
Co-authored-by: Elena Kolevska <elena@kolevska.com>
Co-authored-by: Elena Kolevska <elena-kolevska@users.noreply.github.com>
Co-authored-by: Hristo Temelski <hristo.temelski@redis.com>

maintnotifications/state.go

@@ -0,0 +1,24 @@
+package maintnotifications
+
+// State represents the current state of a maintenance operation
+type State int
+
+const (
+	// StateIdle indicates no upgrade is in progress
+	StateIdle State = iota
+
+	// StateHandoff indicates a connection handoff is in progress
+	StateMoving
+)
+
+// String returns a string representation of the state.
+func (s State) String() string {
+	switch s {
+	case StateIdle:
+		return "idle"
+	case StateMoving:
+		return "moving"
+	default:
+		return "unknown"
+	}
+}