Update vaccine section

[benjystanton]

Updates

• Fix drop-down where you can select a site on the Vaccines page. Only shown if you have 5 or more sites.
• Make sure only or last site can't be deactivated. So don't show 'Deactivate site' link if it's the only site.
• If batches are deactivated as a result of the site being deactivated, show the deactivation reason as 'Site deactivated'
• On the Vaccines page, only show the Active sites and/or Deactivated sites tabs if there is at least 1 Active/Deactivated site
• On the vaccine product page, only show the Active and/or Deactivated tabs if there is at least 1 Active/Deactivated batch
• If no active batches are available and user clicks on vaccine product page, go straight to deactivated tab
• Updated deactivate confirmation msg
• Added error page for vax cannot be saved because site deactivated mid-flow
• Added error page for generic problem deactivating a site
• Added error page for problem deactivating a site because 2 users tried to do this at the same time
• Updated General errors section of prototype index page to show the new errors

[benjystanton]

Have reviewed and thinks it's ready to merge. In the process, I added some urls to the error page links so that they work when clicked.

[benjystanton]

Reviewed as a team together yesterday, so no need for formal review.