Add oauth support

- Support azure, bitbucket, github, gitlab, google providers
- Add authentication page to settings

Co-authored-by: Suraj Kumar <srjkmr1024@gmail.com>
Co-authored-by: Michael Castanieto <mcastanieto@gmail.com>
Co-authored-by: Mike Kim <m.kim4247@gmail.com>

lang/en.json

@@ -1,5 +1,10 @@
 {
     "auth.login": "Login",
+    "auth.login.azure": "Login with Microsoft",
+    "auth.login.bitbucket": "Login with Bitbucket",
+    "auth.login.github": "Login with GitHub",
+    "auth.login.gitlab": "Login with Gitlab",
+    "auth.login.google": "Login with Google",
     "auth.already_registered": "Already registered?",
     "auth.confirm_password": "Confirm password",
     "auth.forgot_password": "Forgot password",
@@ -10,6 +15,7 @@
     "auth.registration_disabled": "Registration is disabled. Please contact the administrator.",
     "auth.reset_password": "Reset password",
     "auth.failed": "These credentials do not match our records.",
+    "auth.failed.callback": "Failed to process callback from login provider.",
     "auth.failed.password": "The provided password is incorrect.",
     "auth.failed.email": "We can't find a user with that e-mail address.",
     "auth.throttle": "Too many login attempts. Please try again in :seconds seconds.",