list: add load queue

_loadLock set true when a load is happening, if another _load is called
when this is happening, the method call is appended to _loadQueue. When
a running _load finishes, it shift()s the _loadQueue and calls the
method from it if there is one.

ts/modules/accounts.ts

@@ -1106,6 +1106,7 @@ export class accountsList extends PaginatedList implements Navigatable, AsTab {
             itemsPerPage: 40,
             maxItemsLoadedForSearch: 200,
             appendNewItems: (resp: PaginatedDTO) => {
+                console.log("append");
                 for (let u of (resp as UsersDTO).users || []) {
                     if (this.users.has(u.id)) {
                         this.users.get(u.id).update(u);
@@ -1121,6 +1122,7 @@ export class accountsList extends PaginatedList implements Navigatable, AsTab {
                 );
             },
             replaceWithNewItems: (resp: PaginatedDTO) => {
+                console.log("replace");
                 let accountsOnDOM = new Map<string, boolean>();
 
                 for (let id of this.users.keys()) {