Feat: reconcile app with scoped permissions (#3434)

* Refactor: refactor multi cluster round trippers

Before adding more RoundTrippers, it would be better to expose common
logic in the utility package.

This commit exports `tryCancelRequest` at `utils` package, and make
`secretMultiClusterRoundTripper` implement `RoundTripperWrapper`
interface to allow chaining multiple round trippers.

Refs #3432

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

* Feat: reconcile app with scoped permissions

Currently, all Application resources are reconciled by the Roles bound
to the controller service account. This behavior gives us the power to
manage resources across multiple namespaces. However, this behavior can
be problematic in the soft-multitenancy environment.

This commit adds `serviceAccountName` to ApplicationSepc to reconcile
Application with the given service account for reconciling Application
with scoped permissions.

Refs #3432

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

* Refactor: extract context setter as method

https://github.com/oam-dev/kubevela/pull/3434#discussion_r825561603

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

* Feat: use annotation instead of spec

https://github.com/oam-dev/kubevela/issues/3432#issuecomment-1066460269

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

* Refactor: unify service account setter caller

https://github.com/oam-dev/kubevela/pull/3434#discussion_r825853612

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

* Refactor: rename GetServiceAccountName

https://github.com/oam-dev/kubevela/pull/3434#discussion_r826514565

Signed-off-by: Sunghoon Kang <hoon@linecorp.com>

cmd/core/main.go

@@ -35,6 +35,7 @@ import (
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 
+	"github.com/oam-dev/kubevela/pkg/auth"
 	ctrlClient "github.com/oam-dev/kubevela/pkg/client"
 	standardcontroller "github.com/oam-dev/kubevela/pkg/controller"
 	commonconfig "github.com/oam-dev/kubevela/pkg/controller/common"
@@ -198,6 +199,7 @@ func main() {
 	restConfig.UserAgent = kubevelaName + "/" + version.GitRevision
 	restConfig.QPS = float32(qps)
 	restConfig.Burst = burst
+	restConfig.Wrap(auth.NewImpersonatingRoundTripper)
 
 	// wrapper the round tripper by multi cluster rewriter
 	if enableClusterGateway {