internal/handlers: add credential pagination support

internal/proto/controller/api/services/v1/credential_service.proto

@@ -84,10 +84,40 @@ message GetCredentialResponse {
 message ListCredentialsRequest {
   string credential_store_id = 1 [json_name = "scope_id"]; // @gotags: `class:"public"`
   string filter = 30 [json_name = "filter"]; // @gotags: `class:"public"`
+  // An opaque token used to continue an existing iteration or
+  // request updated items. If not specified, pagination
+  // will start from the beginning.
+  string list_token = 40 [json_name = "list_token"]; // @gotags: `class:"public"`
+  // The maximum size of a page in this iteration.
+  // If unset, the default page size configured will be used.
+  // If the page_size is greater than the max page size configured,
+  // the page size will be truncated to this number.
+  uint32 page_size = 50 [json_name = "page_size"]; // @gotags: `class:"public"`
 }
 
 message ListCredentialsResponse {
+  // The items returned in this page.
   repeated resources.credentials.v1.Credential items = 1;
+  // The type of response, either "delta" or "complete".
+  // Delta signifies that this is part of a paginated result
+  // or an update to a previously completed pagination.
+  // Complete signifies that it is the last page.
+  string response_type = 2 [json_name = "response_type"]; // @gotags: `class:"public"`
+  // An opaque token used to continue an existing pagination or
+  // request updated items. Use this token in the next list request
+  // to request the next page.
+  string list_token = 3 [json_name = "list_token"]; // @gotags: `class:"public"`
+  // The name of the field which the items are sorted by.
+  string sort_by = 4 [json_name = "sort_by"]; // @gotags: `class:"public"`
+  // The direction of the sort, either "asc" or "desc".
+  string sort_dir = 5 [json_name = "sort_dir"]; // @gotags: `class:"public"`
+  // A list of item IDs that have been removed since they were returned
+  // as part of a pagination. They should be dropped from any client cache.
+  // This may contain items that are not known to the cache, if they were
+  // created and deleted between listings.
+  repeated string removed_ids = 6 [json_name = "removed_ids"]; // @gotags: `class:"public"`
+  // An estimate at the total items available. This may change during pagination.
+  uint32 est_item_count = 7 [json_name = "est_item_count"]; // @gotags: `class:"public"`
 }
 
 message CreateCredentialRequest {