Pinned add-ins shouldn't be pushed out of view when sender address is long enough

(This was originally posted as a bug to https://github.com/OfficeDev/office-js/issues/4954)

In New Outlook and Outlook on the Web, pinned add-ins are pushed out of view when sender address is long enough.
All items on the message surface are pushed to the overflow (...) menu - Reply, Reply All, Forward, add-ins, Apps. The last one standing that won't be dropped is the Emoji button.

Currently, sender address doesn't even have to be as long as in the screenshot above for the items to be pushed out of view.

Current behavior

All items on the message surface are pushed to the overflow (...) menu - Reply, Reply All, Forward, add-ins, Apps. The last one standing that won't be dropped is the Emoji button.
This makes it really hard to increase the adoption of critical add-ins in a company.

If both the Apps and web add-ins are pushed to the overflow menu, the Apps item appears as its own item in the overflow menu. However, it's actually a sub-menu that contains all the user's add-ins. The Apps menu item doesn't indicate it's a sub-menu which you can open, so end users fail to find their add-ins.

Expected behavior

Sender address should be wrapped in such manner that items on the message surface are not moved - there's no reason for the sender address to take over their space.

Steps to reproduce

1. Use either New Outlook for Windows or Outlook on the Web.
2. Locate an email that has longish sender address. See how items on the message surface start to disappear.
3. To increase the effect, decrease the width of your window - more items are dropped out of view.