Bug 21542: Use modal and password field for overdrive password

Bug 21542: Use modal and password field for overdrive password

To test:
 1 - Enabled Overdrive and fill all preferences
 2 - Make sure OverDrivePasswordRequired is true
 3 - Go to opac account
 4 - Log in to overdrive
 5 - Note the input is shown
 6 - Apply patch
 7 - Repeat
 8 - Note popup is now a modal
 9 - Note password is now hidden
10 - Confirm overdrive integration works as before

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>