Bug 22671: Show warning if browser doesn't support applicationCache

Bug 22671: Show warning if browser doesn't support applicationCache

This patch adds a check for browser support for the "applicationCache"
feature required by the offline circulation tool. If the feature is not
available, a message is shown to the user that offline circulation is
disabled.

To test, apply the patch and enable the AllowOfflineCirculation system
preference.

In a browser which supports applicationCache (Firefox < 81, Chrome < 94,
Safari <= 15), go to Circulation -> Built-in offline circulation
interface.

- You should see the standard Offline Circulation menu options: Check
  out, check in, syncrhonize, etc.
- Click "Synchronize," then "Download records."
- The process should complete correctly, updating the "last synced"
  information on the page.

Follow the same steps in a browser which has dropped support for
applicationCache. As soon as you reach the built-in offline circulation
page you should see a message, "Your browser is not compatible..."

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>