feat: App Keys API v2 (#10140)

# Which Problems Are Solved

This PR *partially* addresses #9450 . Specifically, it implements the
resource based API for app keys.

This PR, together with https://github.com/zitadel/zitadel/pull/10077
completes #9450 .

# How the Problems Are Solved

- Implementation of the following endpoints: `CreateApplicationKey`,
`DeleteApplicationKey`, `GetApplicationKey`, `ListApplicationKeys`
- `ListApplicationKeys` can filter by project, app or organization ID.
Sorting is also possible according to some criteria.
  - All endpoints use permissions V2

# TODO

 - [x] Deprecate old endpoints

# Additional Context

Closes #9450

internal/api/grpc/app/v2beta/app_key.go

@@ -0,0 +1,47 @@
+package app
+
+import (
+	"context"
+	"strings"
+
+	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/zitadel/zitadel/internal/api/grpc/app/v2beta/convert"
+	app "github.com/zitadel/zitadel/pkg/grpc/app/v2beta"
+)
+
+func (s *Server) CreateApplicationKey(ctx context.Context, req *app.CreateApplicationKeyRequest) (*app.CreateApplicationKeyResponse, error) {
+	domainReq := convert.CreateAPIClientKeyRequestToDomain(req)
+
+	appKey, err := s.command.AddApplicationKey(ctx, domainReq, "")
+	if err != nil {
+		return nil, err
+	}
+
+	keyDetails, err := appKey.Detail()
+	if err != nil {
+		return nil, err
+	}
+
+	return &app.CreateApplicationKeyResponse{
+		Id:           appKey.KeyID,
+		CreationDate: timestamppb.New(appKey.ChangeDate),
+		KeyDetails:   keyDetails,
+	}, nil
+}
+
+func (s *Server) DeleteApplicationKey(ctx context.Context, req *app.DeleteApplicationKeyRequest) (*app.DeleteApplicationKeyResponse, error) {
+	deletionDetails, err := s.command.RemoveApplicationKey(ctx,
+		strings.TrimSpace(req.GetProjectId()),
+		strings.TrimSpace(req.GetApplicationId()),
+		strings.TrimSpace(req.GetId()),
+		strings.TrimSpace(req.GetOrganizationId()),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &app.DeleteApplicationKeyResponse{
+		DeletionDate: timestamppb.New(deletionDetails.EventDate),
+	}, nil
+}