Add JWT authentication.

Add: JWT authentication in Web API. Related configuration and services are added.

OptixServe.Api/Dtos/Auth.cs

@@ -0,0 +1,12 @@
+namespace OptixServe.Api.Dtos;
+
+public record LoginRequestDto
+{
+    public string? UserName { get; set; }
+    public string? Password { get; set; }
+}
+
+public record LoginResponseDto
+{
+    public string? Token { get; set; }
+}