feat: exchange gRPC server implementation to connectRPC (#10145)

# Which Problems Are Solved

The current maintained gRPC server in combination with a REST (grpc)
gateway is getting harder and harder to maintain. Additionally, there
have been and still are issues with supporting / displaying `oneOf`s
correctly.
We therefore decided to exchange the server implementation to
connectRPC, which apart from supporting connect as protocol, also also
"standard" gRCP clients as well as HTTP/1.1 / rest like clients, e.g.
curl directly call the server without any additional gateway.

# How the Problems Are Solved

- All v2 services are moved to connectRPC implementation. (v1 services
are still served as pure grpc servers)
- All gRPC server interceptors were migrated / copied to a corresponding
connectRPC interceptor.
- API.ListGrpcServices and API. ListGrpcMethods were changed to include
the connect services and endpoints.
- gRPC server reflection was changed to a `StaticReflector` using the
`ListGrpcServices` list.
- The `grpc.Server` interfaces was split into different combinations to
be able to handle the different cases (grpc server and prefixed gateway,
connect server with grpc gateway, connect server only, ...)
- Docs of services serving connectRPC only with no additional gateway
(instance, webkey, project, app, org v2 beta) are changed to expose that
- since the plugin is not yet available on buf, we download it using
`postinstall` hook of the docs

# Additional Changes

- WebKey service is added as v2 service (in addition to the current
v2beta)

# Additional Context

closes #9483

---------

Co-authored-by: Elio Bischof <elio@zitadel.com>

internal/api/grpc/user/v2beta/otp.go

@@ -3,40 +3,42 @@ package user
 import (
 	"context"
 
+	"connectrpc.com/connect"
+
 	object "github.com/zitadel/zitadel/internal/api/grpc/object/v2beta"
 	user "github.com/zitadel/zitadel/pkg/grpc/user/v2beta"
 )
 
-func (s *Server) AddOTPSMS(ctx context.Context, req *user.AddOTPSMSRequest) (*user.AddOTPSMSResponse, error) {
-	details, err := s.command.AddHumanOTPSMS(ctx, req.GetUserId(), "")
+func (s *Server) AddOTPSMS(ctx context.Context, req *connect.Request[user.AddOTPSMSRequest]) (*connect.Response[user.AddOTPSMSResponse], error) {
+	details, err := s.command.AddHumanOTPSMS(ctx, req.Msg.GetUserId(), "")
 	if err != nil {
 		return nil, err
 	}
-	return &user.AddOTPSMSResponse{Details: object.DomainToDetailsPb(details)}, nil
+	return connect.NewResponse(&user.AddOTPSMSResponse{Details: object.DomainToDetailsPb(details)}), nil
 
 }
 
-func (s *Server) RemoveOTPSMS(ctx context.Context, req *user.RemoveOTPSMSRequest) (*user.RemoveOTPSMSResponse, error) {
-	objectDetails, err := s.command.RemoveHumanOTPSMS(ctx, req.GetUserId(), "")
+func (s *Server) RemoveOTPSMS(ctx context.Context, req *connect.Request[user.RemoveOTPSMSRequest]) (*connect.Response[user.RemoveOTPSMSResponse], error) {
+	objectDetails, err := s.command.RemoveHumanOTPSMS(ctx, req.Msg.GetUserId(), "")
 	if err != nil {
 		return nil, err
 	}
-	return &user.RemoveOTPSMSResponse{Details: object.DomainToDetailsPb(objectDetails)}, nil
+	return connect.NewResponse(&user.RemoveOTPSMSResponse{Details: object.DomainToDetailsPb(objectDetails)}), nil
 }
 
-func (s *Server) AddOTPEmail(ctx context.Context, req *user.AddOTPEmailRequest) (*user.AddOTPEmailResponse, error) {
-	details, err := s.command.AddHumanOTPEmail(ctx, req.GetUserId(), "")
+func (s *Server) AddOTPEmail(ctx context.Context, req *connect.Request[user.AddOTPEmailRequest]) (*connect.Response[user.AddOTPEmailResponse], error) {
+	details, err := s.command.AddHumanOTPEmail(ctx, req.Msg.GetUserId(), "")
 	if err != nil {
 		return nil, err
 	}
-	return &user.AddOTPEmailResponse{Details: object.DomainToDetailsPb(details)}, nil
+	return connect.NewResponse(&user.AddOTPEmailResponse{Details: object.DomainToDetailsPb(details)}), nil
 
 }
 
-func (s *Server) RemoveOTPEmail(ctx context.Context, req *user.RemoveOTPEmailRequest) (*user.RemoveOTPEmailResponse, error) {
-	objectDetails, err := s.command.RemoveHumanOTPEmail(ctx, req.GetUserId(), "")
+func (s *Server) RemoveOTPEmail(ctx context.Context, req *connect.Request[user.RemoveOTPEmailRequest]) (*connect.Response[user.RemoveOTPEmailResponse], error) {
+	objectDetails, err := s.command.RemoveHumanOTPEmail(ctx, req.Msg.GetUserId(), "")
 	if err != nil {
 		return nil, err
 	}
-	return &user.RemoveOTPEmailResponse{Details: object.DomainToDetailsPb(objectDetails)}, nil
+	return connect.NewResponse(&user.RemoveOTPEmailResponse{Details: object.DomainToDetailsPb(objectDetails)}), nil
 }