Both the diff commits and the issue summary table suffered regressions

during 6.0 development on mobile, the diff commits list most recently,

and were suboptimal even before this.
The diff commits list used to show a table of all columns (selection

controls/op, message, and author), which was squished on mobile. With

recent changes, it turned into a multi-row display that had review

request background colors peaking out of it.
The issue summary table spanned three rows of content, and was readable,

but had alignment issue and looked quite broken.
Much of this was due to default mobile styling for the tabular base

component.
This change reworks all this to provide a more ideal view on mobile

devices. The tabular component no longer provides default mobile styling

for the table view, instead requiring that each specialization provide

their own styling.
The diff commits list is a table once again, but hides the ID

and author on mobile. This will show the control/op (if appropriate) and

then the message. The rationale is that the ID and author, while nice to

have, are really supplementary and not particularly important

information when screen space is at a premium.
The issue summary table hides the timestamp on mobile and caps the

author information to 25% of the table, leaving the most room for the

comment text. The status icon has been fixed to not have a bunch of

excess padding. This ensures that the key information (status, message,

and just a bit of the author) is available at a glance. The timestamp is

also supplementary and not important to show in this situation.
Both fields are now quite usable even on very narrow mobile devices.

Tested the issue summary table and all filters on desktop and mobile at

different widths.
Tested all variations of the diff commits table (with and without author

information present, which is only when the commit author differs from

the review request author) on desktop and mobile at different widths.