views: Clean up patch-list page

views: Clean up patch-list page

Add ids to table cells, and rename selectors using hyphen delimited
strings to clean up and improve readability of patch-list.html. Also,
create a partial template errors.html for errors that render with form
submission.These changes make the code healthier, ready for change, and
overall more readable.

No user-visible change should be noticed.

Signed-off-by: Raxel Gutierrez <raxel@google.com>
Signed-off-by: Stephen Finucane <stephen@that.guru>
[stephenfin: Addressed merge conflicts and renamed some Python variables
             in snake_case also]