style: sidepanel styling - hidden title quick fix

This commit aims to fix the issue of titles being totally occluded when
the sidebar is dragged to its minimum width.

Signed-off-by: FernandoAscencio <fernando.ascencio.cama@ericsson.com>

packages/core/src/browser/style/sidepanel.css

@@ -26,6 +26,7 @@
   --theia-private-sidebar-scrollbar-rail-width: 7px;
   --theia-private-sidebar-scrollbar-width: 5px;
   --theia-private-sidebar-icon-size: 24px;
+  --theia-private-sidebar-sidepanel-width: 200px;
 }
 
 
@@ -310,6 +311,7 @@
     padding-left: 5px;
     align-items: center;
     background-color: var(--theia-sideBar-background);
+    min-width: var(--theia-private-sidebar-sidepanel-width);
 }
 
 .theia-sidepanel-toolbar .theia-sidepanel-title {