Check the blog item in NavDrawer when opening a blog via notification

There are three scenarios where the selected item in the NavDrawer changes:
1. The user selects an item -> the item is checked automatically.
2. The user pressed back -> already handled in onBackPressed (needs to be extended with #606)
3. The user touched a notification -> handled by this commit.
   
Signed-off-by: goapunk <noobie@goapunks.net>

Closes #889

See merge request !481