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_mapping.go

@@ -208,6 +208,20 @@ func (h *UsersHandler) mapChangeCommandToScimUser(ctx context.Context, user *Sci
 	}
 }
 
+func (h *UsersHandler) mapToScimUsers(ctx context.Context, users []*query.User, md map[string]map[metadata.ScopedKey][]byte) []*ScimUser {
+	result := make([]*ScimUser, len(users))
+	for i, user := range users {
+		userMetadata, ok := md[user.ID]
+		if !ok {
+			userMetadata = make(map[metadata.ScopedKey][]byte)
+		}
+
+		result[i] = h.mapToScimUser(ctx, user, userMetadata)
+	}
+
+	return result
+}
+
 func (h *UsersHandler) mapToScimUser(ctx context.Context, user *query.User, md map[metadata.ScopedKey][]byte) *ScimUser {
 	scimUser := &ScimUser{
 		Resource:     h.buildResourceForQuery(ctx, user),
@@ -364,3 +378,11 @@ func userGrantsToIDs(userGrants []*query.UserGrant) []string {
 	}
 	return converted
 }
+
+func usersToIDs(users []*query.User) []string {
+	ids := make([]string, len(users))
+	for i, user := range users {
+		ids[i] = user.ID
+	}
+	return ids
+}