Allow role based override for the "autoplay" option.

Problem/Motivation

Autoplay works when the a video is primary focus of a page and the user expects to be watching it immediately, it's however annoying for a content admin for example to deal with autoplaying videos when administering the website.

Proposed resolution

I suggest this work entirely with permissions. If a user is assigned to a role with a permission such as "Bypass video autoplay", they never see an autoplay video regardless of the formatter settings.

Remaining tasks

Patch.

User interface changes

New permission.

API changes

None.

Data model changes

None.