[lib] make it possible to send DM ops to all thread members

Summary:
This is a fix for https://phab.comm.dev/D13187#inline-76074.

We going to specify threadID or parenThreadID depending on thread type.

Test Plan: Tested later in the stack - making sure ops are delivered to all members.

Reviewers: tomek, inka

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13193