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/e2e/utils_test.go

@@ -0,0 +1,44 @@
+package e2e
+
+func isTimeout(errMsg string) bool {
+	return contains(errMsg, "i/o timeout") ||
+		contains(errMsg, "deadline exceeded") ||
+		contains(errMsg, "context deadline exceeded")
+}
+
+// isTimeoutError checks if an error is a timeout error
+func isTimeoutError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// Check for various timeout error types
+	errStr := err.Error()
+	return isTimeout(errStr)
+}
+
+// contains checks if a string contains a substring (case-insensitive)
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) &&
+		(s == substr ||
+			(len(s) > len(substr) &&
+				(s[:len(substr)] == substr ||
+					s[len(s)-len(substr):] == substr ||
+					containsSubstring(s, substr))))
+}
+
+func containsSubstring(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}