[Fix #644] Fix fault tree editor layout

- fix canvas and sidebar overlapped by top title bar
- fix missplaced outdated message count indicator for  calculated failure rate in root node

src/components/dashboard/Dashboard.styles.tsx

@@ -3,11 +3,7 @@ import { Theme } from "@mui/material";
 
 const useStyles = makeStyles()((theme: Theme) => {
   return {
-    root: {
-      display: "flex",
-      flexFlow: "column",
-      height: "100vh",
-    },
+    root: {},
     fab: {
       zIndex: 5,
       position: "absolute",