feat: list users scim v2 endpoint (#9187)

# Which Problems Are Solved
- Adds support for the list users SCIM v2 endpoint

# How the Problems Are Solved
- Adds support for the list users SCIM v2 endpoints under `GET
/scim/v2/{orgID}/Users` and `POST /scim/v2/{orgID}/Users/.search`

# Additional Changes
- adds a new function `SearchUserMetadataForUsers` to the query layer to
query a metadata keyset for given user ids
- adds a new function `NewUserMetadataExistsQuery` to the query layer to
query a given metadata key value pair exists
- adds a new function `CountUsers` to the query layer to count users
without reading any rows
- handle `ErrorAlreadyExists` as scim errors `uniqueness`
- adds `NumberLessOrEqual` and `NumberGreaterOrEqual` query comparison
methods
- adds `BytesQuery` with `BytesEquals` and `BytesNotEquals` query
comparison methods

# Additional Context
Part of #8140
Supported fields for scim filters:
* `meta.created`
* `meta.lastModified`
* `id`
* `username`
* `name.familyName`
* `name.givenName`
* `emails` and `emails.value`
* `active` only eq and ne
* `externalId` only eq and ne

internal/api/scim/resources/resource_handler_adapter.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/gorilla/mux"
 
-	"github.com/zitadel/zitadel/internal/api/scim/schemas"
 	"github.com/zitadel/zitadel/internal/api/scim/serrors"
 	"github.com/zitadel/zitadel/internal/zerrors"
 )
@@ -16,22 +15,6 @@ type ResourceHandlerAdapter[T ResourceHolder] struct {
 	handler ResourceHandler[T]
 }
 
-type ListRequest struct {
-	// Count An integer indicating the desired maximum number of query results per page. OPTIONAL.
-	Count uint64 `json:"count" schema:"count"`
-
-	// StartIndex An integer indicating the 1-based index of the first query result. Optional.
-	StartIndex uint64 `json:"startIndex" schema:"startIndex"`
-}
-
-type ListResponse[T any] struct {
-	Schemas      []schemas.ScimSchemaType `json:"schemas"`
-	ItemsPerPage uint64                   `json:"itemsPerPage"`
-	TotalResults uint64                   `json:"totalResults"`
-	StartIndex   uint64                   `json:"startIndex"`
-	Resources    []T                      `json:"Resources"` // according to the rfc this is the only field in PascalCase...
-}
-
 func NewResourceHandlerAdapter[T ResourceHolder](handler ResourceHandler[T]) *ResourceHandlerAdapter[T] {
 	return &ResourceHandlerAdapter[T]{
 		handler,
@@ -62,6 +45,15 @@ func (adapter *ResourceHandlerAdapter[T]) Delete(r *http.Request) error {
 	return adapter.handler.Delete(r.Context(), id)
 }
 
+func (adapter *ResourceHandlerAdapter[T]) List(r *http.Request) (*ListResponse[T], error) {
+	request, err := readListRequest(r)
+	if err != nil {
+		return nil, err
+	}
+
+	return adapter.handler.List(r.Context(), request)
+}
+
 func (adapter *ResourceHandlerAdapter[T]) Get(r *http.Request) (T, error) {
 	id := mux.Vars(r)["id"]
 	return adapter.handler.Get(r.Context(), id)
@@ -71,7 +63,7 @@ func (adapter *ResourceHandlerAdapter[T]) readEntityFromBody(r *http.Request) (T
 	entity := adapter.handler.NewResource()
 	err := json.NewDecoder(r.Body).Decode(entity)
 	if err != nil {
-		if zerrors.IsZitadelError(err) {
+		if serrors.IsScimOrZitadelError(err) {
 			return entity, err
 		}