style: sidebar styling (#194)

* style: sidebar styling

* style: hover and selected colors

* chore: split the sidebar items into separate component

* style: pretty much finished except for status button

* feat: sidebar status button as a separate component

* chore: spacing definition

* style: size of the status text

* fix: hiden navigation on small height screens

package.json

@@ -25,7 +25,7 @@
   },
   "dependencies": {
     "@ethersphere/bee-js": "1.2.0",
-    "@material-ui/core": "4.11.4",
+    "@material-ui/core": "4.12.3",
     "@material-ui/icons": "4.11.2",
     "@material-ui/lab": "4.0.0-alpha.57",
     "@types/react-router": "5.1.13",