add SUIT CSS name convention to old .navdrawer-container and inner elements

This PR address two issues:

1. Add SUIT CSS name convention to old `.navdrawer-container` element with its own modifiers, descendants and states
2. Be more specific on CSS declarations for elements on `.navdrawer-container`. This comes from the need of adding a social network widget on the menu and getting generic selectors messing with my component. This solves this kind of specificity problem on custom implementations of the menu