Improve UI for group milestone and project milestone pages

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Dont check for milestone description on group milestone page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'fix-ui-milestone' into 'master'

Improve UI for milestone pages

See merge request !1356