Remove No Authentication mode from Kavita (#1006)

* Moved the Server Settings out into a button on nav header

* Refactored Mange Users page to the new design (skeleton). Implemented skeleton code for Invite User.

* Hashed out more of the code, but need to move all the email code to a Kavita controlled API server due to password credentials.

* Cleaned up some warnings

* When no user exists for an api key in Plugin controller, throw 401.

* Hooked in the ability to check if the Kavita instance can be accessed externally so we can determine if the user can invite or not.

* Hooked up some logic if the user's server isn't accessible, then default to old flow

* Basic flow is working for confirm email. Needs validation, error handling, etc.

* Refactored Password validation to account service

* Cleaned up the code in confirm-email to work much better.

* Refactored the login page to have a container functionality, so we can reuse the styles on multiple pages (registration pages). Hooked up the code for confirm email.

* Messy code, but making progress. Refactored Register to be used only for first time user registration. Added a new register component to handle first time flow only.

* Invite works much better, still needs a bit of work for non-accessible server setup. Started work on underlying manage users page to meet new design.

* Changed (you) to a star to indicate who you're logged in as.

* Inviting a user is now working and tested fully.

* Removed the register member component as we now have invite and confirm components.

* Editing a user is now working. Username change and Role/Library access from within one screen. Email changing is on hold.

* Cleaned up code for edit user and disabled email field for now.

* Cleaned up the code to indicate changing a user's email is not possible.

* Implemented a migration for existing accounts so they can validate their emails and still login.

* Change url for email server

* Implemented the ability to resend an email confirmation code (or regenerate for non accessible servers). Fixed an overflow on the confirm dialog.

* Removed all code around disabling authentication. Users that were already disabled can look up their password on the wiki.

API/Entities/Enums/ServerSettingKey.cs

@@ -47,6 +47,7 @@ namespace API.Entities.Enums
         /// <summary>
         /// Is Authentication needed for non-admin accounts
         /// </summary>
+        /// <remarks>Deprecated. This is no longer used v0.5.1+. Assume Authentication is always in effect</remarks>
         [Description("EnableAuthentication")]
         EnableAuthentication = 8,
         /// <summary>