FileManager Template design updates

[silviyaboteva]

There are 2 things that doesn't follow the Figma design:

1. The Breadcrumb panel should have background and bottom border + refer to Figma file for size metrics:
   Class k-filemanager-breadcrumb should also be added to the nav

2. Rename function should be enabled by inline editing instead of Dialog window

Further information could be found in this issue: telerik/kendo-themes#3039