Add support for FIDO U2F (#3971)

* Add support for U2F

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add vendor library
Add missing translations

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Minor improvements

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F support for Firefox, Chrome (Android) by introducing a custom JS library
Add U2F error handling

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F login page to OAuth

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Move U2F user settings to a separate file

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add unit tests for u2f model
Renamed u2f table name

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Fix problems caused by refactoring

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F documentation

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Remove not needed console.log-s

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add default values to app.ini.sample
Add FIDO U2F to comparison

Signed-off-by: Jonas Franz <info@jonasfranz.software>

models/fixtures/u2f_registration.yml

@@ -0,0 +1,7 @@
+-
+  id: 1
+  name: "U2F Key"
+  user_id: 1
+  counter: 0
+  created_unix: 946684800
+  updated_unix: 946684800