perf(actionsv2): execution target router (#10564)

# Which Problems Are Solved

The event execution system currently uses a projection handler that
subscribes to and processes all events for all instances. This creates a
high static cost because the system over-fetches event data, handling
many events that are not needed by most instances. This inefficiency is
also reflected in high "rows returned" metrics in the database.

# How the Problems Are Solved

Eliminate the use of a project handler. Instead, events for which
"execution targets" are defined, are directly pushed to the queue by the
eventstore. A Router is populated in the Instance object in the authz
middleware.

- By joining the execution targets to the instance, no additional
queries are needed anymore.
- As part of the instance object, execution targets are now cached as
well.
- Events are queued within the same transaction, giving transactional
guarantees on delivery.
- Uses the "insert many fast` variant of River. Multiple jobs are queued
in a single round-trip to the database.
- Fix compatibility with PostgreSQL 15

# Additional Changes

- The signing key was stored as plain-text in the river job payload in
the DB. This violated our [Secrets
Storage](https://zitadel.com/docs/concepts/architecture/secrets#secrets-storage)
principle. This change removed the field and only uses the encrypted
version of the signing key.
- Fixed the target ordering from descending to ascending.
- Some minor linter warnings on the use of `io.WriteString()`.

# Additional Context

- Introduced in https://github.com/zitadel/zitadel/pull/9249
- Closes https://github.com/zitadel/zitadel/issues/10553
- Closes https://github.com/zitadel/zitadel/issues/9832
- Closes https://github.com/zitadel/zitadel/issues/10372
- Closes https://github.com/zitadel/zitadel/issues/10492

---------

Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>
(cherry picked from commit a9ebc06c77)

internal/query/target_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/zitadel/zitadel/internal/crypto"
 	"github.com/zitadel/zitadel/internal/domain"
+	target_domain "github.com/zitadel/zitadel/internal/execution/target"
 	"github.com/zitadel/zitadel/internal/zerrors"
 )
 
@@ -103,7 +104,7 @@ func Test_TargetPrepares(t *testing.T) {
 							testNow,
 							"ro",
 							"target-name",
-							domain.TargetTypeWebhook,
+							target_domain.TargetTypeWebhook,
 							1 * time.Second,
 							"https://example.com",
 							true,
@@ -130,7 +131,7 @@ func Test_TargetPrepares(t *testing.T) {
 							ResourceOwner: "ro",
 						},
 						Name:             "target-name",
-						TargetType:       domain.TargetTypeWebhook,
+						TargetType:       target_domain.TargetTypeWebhook,
 						Timeout:          1 * time.Second,
 						Endpoint:         "https://example.com",
 						InterruptOnError: true,
@@ -158,7 +159,7 @@ func Test_TargetPrepares(t *testing.T) {
 							testNow,
 							"ro",
 							"target-name1",
-							domain.TargetTypeWebhook,
+							target_domain.TargetTypeWebhook,
 							1 * time.Second,
 							"https://example.com",
 							true,
@@ -175,7 +176,7 @@ func Test_TargetPrepares(t *testing.T) {
 							testNow,
 							"ro",
 							"target-name2",
-							domain.TargetTypeWebhook,
+							target_domain.TargetTypeWebhook,
 							1 * time.Second,
 							"https://example.com",
 							false,
@@ -192,7 +193,7 @@ func Test_TargetPrepares(t *testing.T) {
 							testNow,
 							"ro",
 							"target-name3",
-							domain.TargetTypeAsync,
+							target_domain.TargetTypeAsync,
 							1 * time.Second,
 							"https://example.com",
 							false,
@@ -219,7 +220,7 @@ func Test_TargetPrepares(t *testing.T) {
 							ResourceOwner: "ro",
 						},
 						Name:             "target-name1",
-						TargetType:       domain.TargetTypeWebhook,
+						TargetType:       target_domain.TargetTypeWebhook,
 						Timeout:          1 * time.Second,
 						Endpoint:         "https://example.com",
 						InterruptOnError: true,
@@ -238,7 +239,7 @@ func Test_TargetPrepares(t *testing.T) {
 							ResourceOwner: "ro",
 						},
 						Name:             "target-name2",
-						TargetType:       domain.TargetTypeWebhook,
+						TargetType:       target_domain.TargetTypeWebhook,
 						Timeout:          1 * time.Second,
 						Endpoint:         "https://example.com",
 						InterruptOnError: false,
@@ -257,7 +258,7 @@ func Test_TargetPrepares(t *testing.T) {
 							ResourceOwner: "ro",
 						},
 						Name:             "target-name3",
-						TargetType:       domain.TargetTypeAsync,
+						TargetType:       target_domain.TargetTypeAsync,
 						Timeout:          1 * time.Second,
 						Endpoint:         "https://example.com",
 						InterruptOnError: false,
@@ -319,7 +320,7 @@ func Test_TargetPrepares(t *testing.T) {
 						testNow,
 						"ro",
 						"target-name",
-						domain.TargetTypeWebhook,
+						target_domain.TargetTypeWebhook,
 						1 * time.Second,
 						"https://example.com",
 						true,
@@ -340,7 +341,7 @@ func Test_TargetPrepares(t *testing.T) {
 					ResourceOwner: "ro",
 				},
 				Name:             "target-name",
-				TargetType:       domain.TargetTypeWebhook,
+				TargetType:       target_domain.TargetTypeWebhook,
 				Timeout:          1 * time.Second,
 				Endpoint:         "https://example.com",
 				InterruptOnError: true,