[lib][web][native] Update createRealThreadFromPendingThread to handle thick thread creation

Summary:
issues:
ENG-8442, ENG-9122

Test Plan:
Tested by setting usingOlmViaTunnelbrokerForDMs to true. Not setting this flag yet, because it has other effects.
Tested that a thick thread gets created on both web and native.

Tested that if the flag is set to false, thin threads are created correctly

There is a problem with navigation - on both platfrms when the thick thread is created the user is not navigate to it. Instead they stay in the pending thread. I will address that in ENG-9147

Reviewers: tomek, kamil

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13244