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/user.go

@@ -183,6 +183,35 @@ func (h *UsersHandler) Get(ctx context.Context, id string) (*ScimUser, error) {
 	return h.mapToScimUser(ctx, user, metadata), nil
 }
 
+func (h *UsersHandler) List(ctx context.Context, request *ListRequest) (*ListResponse[*ScimUser], error) {
+	q, err := h.buildListQuery(ctx, request)
+	if err != nil {
+		return nil, err
+	}
+
+	if request.Count == 0 {
+		count, err := h.query.CountUsers(ctx, q)
+		if err != nil {
+			return nil, err
+		}
+
+		return newListResponse(count, q.SearchRequest, make([]*ScimUser, 0)), nil
+	}
+
+	users, err := h.query.SearchUsers(ctx, q, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	metadata, err := h.queryMetadataForUsers(ctx, usersToIDs(users.Users))
+	if err != nil {
+		return nil, err
+	}
+
+	scimUsers := h.mapToScimUsers(ctx, users.Users, metadata)
+	return newListResponse(users.SearchResponse.Count, q.SearchRequest, scimUsers), nil
+}
+
 func (h *UsersHandler) queryUserDependencies(ctx context.Context, userID string) ([]*command.CascadingMembership, []string, error) {
 	userGrantUserQuery, err := query.NewUserGrantUserIDSearchQuery(userID)
 	if err != nil {