[native] Fix display of TooltipInlineEngagement

Summary:
This diff does two things:

1. We need to pass positioning from TooltipInlineEngagement to InlineEngagement in order to make sure that the reactions and sidebar button appear in the same order. The point of TooltipInlineEngagement is to appear directly over InlineEngagement to make the animation look good; if the order of buttons is different, the animation is ruined.
2. After passing positioning to InlineEngagement, I was able to clean up some of the styles used in TooltipInlineEngagement.

Depends on D13676

Test Plan: On my local iOS simulator, I tested 6 cases: multimedia, text, and robotext, each sent from the viewer and from somebody else. I made sure each test case had a sidebar and a reaction. In all cases, I made sure that the inline engagement appears exactly in the place it should.

Reviewers: tomek

Reviewed By: tomek

Differential Revision: https://phab.comm.dev/D13677