Are "White lies" which don't harm anyone and are not used for selfish or evil purposes still Haram? Like for avoiding awkward situations or avoiding waste of time.

White lies are haram even if one believes no bad consequence will occur by them. Yes, there is something called Tawriyah, which means you are not lying technically but you say something true that the other person perceives differently. For example, your friend invites you for dinner and you don’t really want to go, so you tell him “I had dinner” meaning yesterday. This is technically not a lie and so it would be permissible.