fix: remove action feature flag and include execution (#9727)

# Which Problems Are Solved

Actions v2 is not a feature flag anymore, include functionality on
executions is not used and json tags of proto messages are handled
incorrectly.

# How the Problems Are Solved

- Remove actions from the feature flags on system and instance level
- Remove include type on executions, only in the API, later maybe in the
handling logic as well
- Use protojson in request and response handling of actions v2

# Additional Changes

- Correct integration tests for request and response handling
- Use json.RawMessage for events, so that the event payload is not
base64 encoded
- Added separate context for async webhook calls, that executions are
not cancelled when called async

# Additional Context

Related to #9759 
Closes #9710

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/api/grpc/feature/v2/integration_test/feature_test.go

@@ -211,7 +211,6 @@ func TestServer_GetSystemFeatures(t *testing.T) {
 			assertFeatureFlag(t, tt.want.OidcTriggerIntrospectionProjections, got.OidcTriggerIntrospectionProjections)
 			assertFeatureFlag(t, tt.want.OidcLegacyIntrospection, got.OidcLegacyIntrospection)
 			assertFeatureFlag(t, tt.want.UserSchema, got.UserSchema)
-			assertFeatureFlag(t, tt.want.Actions, got.Actions)
 		})
 	}
 }
@@ -374,10 +373,6 @@ func TestServer_GetInstanceFeatures(t *testing.T) {
 					Enabled: false,
 					Source:  feature.Source_SOURCE_UNSPECIFIED,
 				},
-				Actions: &feature.FeatureFlag{
-					Enabled: false,
-					Source:  feature.Source_SOURCE_UNSPECIFIED,
-				},
 			},
 		},
 		{
@@ -387,7 +382,6 @@ func TestServer_GetInstanceFeatures(t *testing.T) {
 					LoginDefaultOrg:                     gu.Ptr(true),
 					OidcTriggerIntrospectionProjections: gu.Ptr(false),
 					UserSchema:                          gu.Ptr(true),
-					Actions:                             gu.Ptr(true),
 				})
 				require.NoError(t, err)
 			},
@@ -408,10 +402,6 @@ func TestServer_GetInstanceFeatures(t *testing.T) {
 					Enabled: true,
 					Source:  feature.Source_SOURCE_INSTANCE,
 				},
-				Actions: &feature.FeatureFlag{
-					Enabled: true,
-					Source:  feature.Source_SOURCE_INSTANCE,
-				},
 			},
 		},
 		{
@@ -445,10 +435,6 @@ func TestServer_GetInstanceFeatures(t *testing.T) {
 					Enabled: false,
 					Source:  feature.Source_SOURCE_UNSPECIFIED,
 				},
-				Actions: &feature.FeatureFlag{
-					Enabled: false,
-					Source:  feature.Source_SOURCE_UNSPECIFIED,
-				},
 			},
 		},
 	}