Adds Configuration Manager + tests

Core/Configurations/ConfigurationManager/JsonConfiguration.cs

@@ -0,0 +1,31 @@
+using Newtonsoft.Json.Linq;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Primitives;
+using System.Data;
+
+namespace Configuration.Core;
+    public class JsonConfiguration : IConfiguration
+{
+    private readonly JObject _data;
+    private readonly IChangeToken _changeToken;
+
+    public JsonConfiguration(JObject data, IChangeToken changeToken)
+    {
+        _data = data;
+        _changeToken = changeToken;
+    }
+
+    public string this[string key]
+    {
+        get => _data.SelectToken(key.Replace(":", "."))?.ToString();
+        set => throw new NotImplementedException();
+    }
+
+    public IConfigurationSection GetSection(string key) =>
+        new JsonConfigurationSection(_data, key);
+
+    public IEnumerable<IConfigurationSection> GetChildren() =>
+        _data.Properties().Select(p => new JsonConfigurationSection(_data, p.Name));
+
+    public IChangeToken GetReloadToken() => _changeToken;
+}