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/org/v2/query.go

@@ -3,6 +3,8 @@ package org
 import (
 	"context"
 
+	"connectrpc.com/connect"
+
 	"github.com/zitadel/zitadel/internal/api/authz"
 	"github.com/zitadel/zitadel/internal/api/grpc/object/v2"
 	"github.com/zitadel/zitadel/internal/domain"
@@ -11,36 +13,36 @@ import (
 	"github.com/zitadel/zitadel/pkg/grpc/org/v2"
 )
 
-func (s *Server) ListOrganizations(ctx context.Context, req *org.ListOrganizationsRequest) (*org.ListOrganizationsResponse, error) {
+func (s *Server) ListOrganizations(ctx context.Context, req *connect.Request[org.ListOrganizationsRequest]) (*connect.Response[org.ListOrganizationsResponse], error) {
 	queries, err := listOrgRequestToModel(ctx, req)
 	if err != nil {
 		return nil, err
 	}
-	orgs, err := s.query.SearchOrgs(ctx, queries, s.checkPermission)
+	orgs, err := s.query.SearchOrgs(ctx, queries.Msg, s.checkPermission)
 	if err != nil {
 		return nil, err
 	}
-	return &org.ListOrganizationsResponse{
+	return connect.NewResponse(&org.ListOrganizationsResponse{
 		Result:  organizationsToPb(orgs.Orgs),
 		Details: object.ToListDetails(orgs.SearchResponse),
-	}, nil
+	}), nil
 }
 
-func listOrgRequestToModel(ctx context.Context, req *org.ListOrganizationsRequest) (*query.OrgSearchQueries, error) {
-	offset, limit, asc := object.ListQueryToQuery(req.Query)
-	queries, err := orgQueriesToQuery(ctx, req.Queries)
+func listOrgRequestToModel(ctx context.Context, req *connect.Request[org.ListOrganizationsRequest]) (*connect.Response[query.OrgSearchQueries], error) {
+	offset, limit, asc := object.ListQueryToQuery(req.Msg.Query)
+	queries, err := orgQueriesToQuery(ctx, req.Msg.Queries)
 	if err != nil {
 		return nil, err
 	}
-	return &query.OrgSearchQueries{
+	return connect.NewResponse(&query.OrgSearchQueries{
 		SearchRequest: query.SearchRequest{
 			Offset:        offset,
 			Limit:         limit,
-			SortingColumn: fieldNameToOrganizationColumn(req.SortingColumn),
+			SortingColumn: fieldNameToOrganizationColumn(req.Msg.SortingColumn),
 			Asc:           asc,
 		},
 		Queries: queries,
-	}, nil
+	}), nil
 }
 
 func orgQueriesToQuery(ctx context.Context, queries []*org.SearchQuery) (_ []query.SearchQuery, err error) {