Fix the title of the toggle dropdown button

Before when you choose the way of `sort` instead it display the title correctly it was just apply the humanize helper in sort value.

E.g.

When you choose `Last updated` it should display the title `Last updated` instead of `Recently updated`. This fix makes this correctly displays the title.

Change the implementation of the `link_to` `filter_branches_path`

- Change the value of the `params[:sort]` in `link_to`. E.g. instead of using `'recently_updated'` is now using `sort_value_recently_updated`.

- Change the values of the case in the `branches_sorted_by` method for the values it receives in the `params[:sort]` that are: `nil`, `'name'`, `'updated_desc'`, `'updated_asc'`.