fix: return z-index value to sticky-toolbar

Author: Полеводин Дмитрий Игоревич (4094029)

src/styles/_zindex.scss

@@ -6,5 +6,5 @@ $z-index-map: (
     'img-settings-button': 2,
     'table-view-button': 100,
     'table-cell-button': 110,
-    'sticky-toolbar': 990,
+    'sticky-toolbar': 2000,
 );