Make notes full width beneath forms

* Notes were restricted to half the page, and within that fact check
email content restricted even further. This made it very hard to read
fact check email content.
* Remove the left/right alignment of note forms and note entries,
giving notes a full width to be viewed
* Put edition notes and important notes side by side
Cleanup edition history

* Render history as a list rather than a definition list, using the
time and the action as the heading.
* Place fact check responses in a blockquote, this styles the emails
with a larger font size and indents them from the title for easier
scanning of headings
Tweak notes help text

* Bring copy closer inline with style guide
* Avoid using “should”
Don't use an ampersand in the tab title

https://www.gov.uk/design-principles/style-guide/style-points#style-ampe
rsand
Update notes title to reflect history too
Move notes forms to modals

* The notes forms aren’t used as often as the history and notes view,
the forms get in the way.
* Use the same modal mechanism as the workflow buttons to add edition
notes and important notes. (Note that this doesn’t work without
Javascript, but you can’t currently get to this tab if Javascript is
disabled)
* Move preview and factcheck details to beneath tab title
* Add primary-styled buttons to open note modals
Merge pull request #264 from alphagov/better-notes

Improve edition history and notes