Please make namespaces navigation more user friendly

[fpopic]

Is your feature request related to a problem? Please describe.
Whenever I want to change the namespace in Vault Enterprise I have to press a couple of back buttons in the tiny window in the left bottom corner, while the black sidebar margin is empty.

Describe the solution you'd like
I would like to have more user-friendly namespace navigation (as the list structure) that is always visible in the left sidebar (filling the space in the left sidebar). I would like to switch namespaces by pressing the namespace name with one click, without the need for pressing the back button to see all available namespaces.