Responsive css for the media modal

[azaozz]

The current goal is to make the new media modal work/look well on tablets and small-screen laptops (same as the rest of the admin).

[azaozz]

In 22615-2.patch:

• At 900px width reduces the width of the left and right areas and reorders the image options so labels ate above the fields.
• 600px is the min-width. The modal has position: absolute so it can be scrolled horizontally.
• Includes couple of fixes for 22615.patch

[nacin]

Good start.

[koopersmith]

Concur. Commit, mark as see, bump to low priority.

[koopersmith]

...things that begin with "dev".

[koopersmith]

In 22887:

Responsive CSS for the media modal. props azaozz. see #22615, #21390.

[ocean90]

22615.3.patch​ improves the media selection in the toolbar.

[koopersmith]

attachment:22615.4.diff​ builds off of​​ attachment:22615.3.patch​:

Needs RTL after the current patch on #22453 is committed.

• Tweaks media selection improvements, moves them to the earlier break point.
• Adjusts modal size, dashed line position, separator size, padding on sidebar, and menu size.

[ocean90]

attachment:22615.5.diff​​ adds a lot of RTL stuff. And refreshes 22615.4.diff​. And looks good.

(Except that the search form isn't bumped quickly enough.)

[azaozz]

22615.5.diff looks good. The only thing I've noticed is the rounded search field in iOS, but that's the same as other search fields in the admin.

[ryan]

In 22960:

Responsive and RTL css improvements or the media modal.

Props ocean90, koopersmith
see #22615

[nacin]

This ticket is basically just open for any additional cleanups or adjustments we want to make; it's a rider.

[nacin]

If ocean90 or azaozz has anything else here, please re-open. Thanks.