Beta features: Text field for inline comments is set by diff width, can require horizontal scrolling

[badshah400]

Issue Description

When entering comments inline against a request, the user is presented with a text field that is determined by the contents of the file (specfile or patch which are part of the request) itself. This can become rather unwieldy for entering text, as shown in the screenshots attached below.

Expected Result

A normal width text box, limited within the boundary of div id=#diff-list-coot-spec (or whatever file being reviewed) that does not force me to scroll horizontally.

How to Reproduce

1. Go to [https://build.opensuse.org/request/show/1170443/changes]
2. Ensure beta features are turned on, to allow inline commenting.
3. Try adding comments inline against the spec file in the review.
4. See huge width text box.

Screenshot