add drag and drop capabilities for the order of cluster icons on the side bar (#623)

* add drag and drop capabilities for the order of cluster icons on the side bar

* add type annotations for better clarity

* fix clusters staying in previously icon reordered workspaces

* add some tests to cluster-store

Signed-off-by: Sebastian Malton <smalton@mirantis.com>

Co-authored-by: Sebastian Malton <smalton@mirantis.com>

src/renderer/components/cluster-icon/cluster-icon.scss

@@ -4,6 +4,7 @@
   position: relative;
   border-radius: $radius;
   padding: $radius;
+  margin-bottom: $padding * 2;
   user-select: none;
   cursor: pointer;