Provisioning: Do not allow deletion of provisioned dashboards (#16211)

* Unprovision dashboard in case of DisableDeletion = true

* Rename command struct

* Handle removed provision files

* Allow html in confirm-modal

* Do not show confirm button without onConfirm

* Show dialog on deleting provisioned dashboard

* Changed DeleteDashboard to DeleteProvisionedDashboard

* Remove unreachable return

* Add provisioned checks to API

* Remove filter func

* Fix and add tests for deleting dashboards

* Change delete confirm text

* Added and used pkg/errors for error wrapping

pkg/util/math.go

@@ -0,0 +1,17 @@
+package util
+
+// MaxInt returns the larger of x or y.
+func MaxInt(x, y int) int {
+	if x < y {
+		return y
+	}
+	return x
+}
+
+// MinInt returns the smaller of x or y.
+func MinInt(x, y int) int {
+	if x > y {
+		return y
+	}
+	return x
+}