[EastSussex] UI improvements to encourage good updates

ESCC advised us of concerns that users:

 * were unaware of how much of their report/update would be visible
 on the site
    - make "public" text more visible.
    - label is presented as fairly flat, with the cursor suppressed (to
      avoid it looking like a button) but with an explanatory tooltip.
      The intent is for it to be highly visible, but not too startling.
    - https://github.com/mysociety/FixMyStreet-Commercial/issues/642

 * often comment on an existing report when instead creating a new
 report would be more appropriate.
    - Present two buttons, one to create a new report in the same
      location, another to open the comment box.
    - (this functionality degrades without Javascript, by simply showing
      the comment box by default.)
    - https://github.com/mysociety/FixMyStreet-Commercial/issues/641

Most templates have been split into partials, to avoid long-term
forking, however update-form.html is still forked from fixmystreet,
which would ideally be fixed in a future commit.
[EastSussex] Fix layout without JS

The non-js view positioned the map badly (over the issue text).
Merge branch 'issues/commercial/641-642-eastsussex-candidate'