adjust the max shown items number to the result returned by the research

client/src/app/instance/search/components/result/datatable.component.html

@@ -58,10 +58,10 @@
     <div class="col">
         Show 
         <select class="custom-select" (change)="changeNbItems($event.target.value)">
-            <option value="10" selected="true">10</option>
-            <option value="20">20</option>
-            <option value="50">50</option>
-            <option value="100">100</option>
+            <option *ngIf="dataLength <= 10 || dataLength >10" value="10" selected="true">10</option>
+            <option *ngIf="dataLength >10" value="20">20</option>
+            <option *ngIf="dataLength > 20" value="50">50</option>
+            <option *ngIf="dataLength > 50" value="100">100</option>
         </select>
         entries
     </div>