App: Authentication updates (#6536)

- Updates API key extraction to also accept "Bearer" auth header. This is necessary for non-cookie based SignalR connections.
- Adds authentication related models to the client lib
- Succeeds and replaces #6484.

BTCPayServer.Client/App/Models/AuthenticationResult.cs

@@ -0,0 +1,7 @@
+#nullable enable
+namespace BTCPayServer.Client.App.Models;
+
+public class AuthenticationResponse
+{
+    public string? AccessToken { get; set; }
+}

BTCPayServer.Client/App/Models/LoginRequest.cs

@@ -0,0 +1,10 @@
+#nullable enable
+namespace BTCPayServer.Client.App.Models;
+
+public class LoginRequest
+{
+    public string? Email { get; set; }
+    public string? Password { get; set; }
+    public string? TwoFactorCode { get; set; }
+    public string? TwoFactorRecoveryCode { get; set; }
+}

BTCPayServer.Client/App/Models/ResetPasswordRequest.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Client.App.Models;
+
+public class ResetPasswordRequest
+{
+    public string Email { get; set; }
+    public string ResetCode { get; set; }
+    public string NewPassword { get; set; }
+}