R1:ba835fe0eced

Seperate repository home and browse view in tab menu

Summary:
The tab menu in a repository can be a bit confusing. The first tab will be rendered active for two distinctive states:

- the home view in the currently selected branch
- the browse view in the currently selected branch

This diff will give the home view a dedicated extra tab. When switching the branches, we won't switch between home and browse view like it is done now.

And I have changed the crumb text for the browse view to "Code" to match…