Feature/token service (#1785)

* Implement draft token service

* Add tokenizer and factory

* Handle expiring tokens through base class

* Allow direct token validity checks

* Add safe unprotect to tokenizer

* Add interface to tokenizer factory

* Use tokenizer

* Fix rebase

* Handle cleartext prefix in tokenizer base

* Use epoch milliseconds for expiration in tokens

* Use tokenizers

* Test tokens

* Linter fixes

* Add TokenizerFactory to DI services

* Test epoch milliseconds deserialization

* Use separate injectables for each token type

* Fix directory

* Add functional unprotect to token

* Fix namespace and correct object names

* Remove Tokenable interface

* Test remaining Tokens classes

* Dotnet format

* Fix sut provider errors with update

* Remove useless property

Co-authored-by: Hinton <oscar@oscarhinton.com>

src/Core/Tokens/ExpiringTokenable.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Text.Json.Serialization;
+using Bit.Core.Utilities;
+
+namespace Bit.Core.Tokens
+{
+    public abstract class ExpiringTokenable : Tokenable
+    {
+        [JsonConverter(typeof(EpochDateTimeJsonConverter))]
+        public DateTime ExpirationDate { get; set; }
+        public override bool Valid => ExpirationDate > DateTime.UtcNow && TokenIsValid();
+
+        protected abstract bool TokenIsValid();
+    }
+}