As an administrator I want to globally disable diff transcoding to avoid performance problems

Currently, diff transcoding can be enabled and disabled on a per-repository basis. In Using diff transcoding in Bitbucket Server we describe that enabling this feature has implications for performance.

Problem

If users enable diff transcoding for their repositories performance of the server may suffer, and the admin has no way of disabling diff transcoding except by disabling it on all repositories one by one.

Expected solution

An administrator should have a way of disabling diff transcoding on a global level.