feat: Add unit tests and fakes for Crestron environment and data store

- Introduced `FakeCrestronEnvironment` and `FakeEthernetHelper` for testing purposes.
- Implemented `InMemoryCrestronDataStore` to facilitate unit tests for data storage.
- Created `DebugServiceTests` to validate the behavior of debug-related services.
- Added project files for unit tests targeting .NET 9.0 with necessary dependencies.
- Developed production adapters (`CrestronConsoleAdapter`, `CrestronDataStoreAdapter`, `CrestronEnvironmentAdapter`, `CrestronEthernetAdapter`) to interface with the Crestron SDK.
- Updated `Debug` class to utilize injected service abstractions instead of direct SDK calls.
- Enhanced `ControlSystem` initialization to register service adapters before usage.

src/PepperDash.Core.Abstractions/Enums.cs

@@ -0,0 +1,100 @@
+namespace PepperDash.Core.Abstractions;
+
+/// <summary>
+/// Mirrors Crestron's <c>eDevicePlatform</c> without requiring the Crestron SDK.
+/// </summary>
+public enum DevicePlatform
+{
+    /// <summary>Hardware appliance (e.g. CP4, MC4).</summary>
+    Appliance,
+    /// <summary>Crestron Virtual Control / server runtime.</summary>
+    Server,
+}
+
+/// <summary>
+/// Mirrors Crestron's <c>eRuntimeEnvironment</c>.
+/// </summary>
+public enum RuntimeEnvironment
+{
+    /// <summary>SimplSharpPro program slot (hardware 4-series).</summary>
+    SimplSharpPro,
+    /// <summary>SimplSharp (older 3-series or server environments).</summary>
+    SimplSharp,
+    /// <summary>Any other environment — check for completeness.</summary>
+    Other,
+}
+
+/// <summary>
+/// Mirrors Crestron's <c>ConsoleAccessLevelEnum</c>.
+/// </summary>
+public enum ConsoleAccessLevel
+{
+    AccessAdministrator = 0,
+    AccessOperator = 1,
+    AccessProgrammer = 2,
+}
+
+/// <summary>
+/// Mirrors Crestron's <c>eProgramStatusEventType</c>.
+/// </summary>
+public enum ProgramStatusEventType
+{
+    Starting,
+    Stopping,
+    Paused,
+    Resumed,
+}
+
+/// <summary>
+/// Mirrors the event type used by Crestron's <c>EthernetEventArgs</c>.
+/// </summary>
+public enum EthernetEventType
+{
+    LinkDown = 0,
+    LinkUp = 1,
+}
+
+/// <summary>
+/// Event args for Crestron ethernet link events.
+/// </summary>
+public class PepperDashEthernetEventArgs : EventArgs
+{
+    public EthernetEventType EthernetEventType { get; }
+    public short EthernetAdapter { get; }
+
+    public PepperDashEthernetEventArgs(EthernetEventType eventType, short adapter)
+    {
+        EthernetEventType = eventType;
+        EthernetAdapter = adapter;
+    }
+}
+
+/// <summary>
+/// Mirrors the set of <c>CrestronEthernetHelper.ETHERNET_PARAMETER_TO_GET</c> values
+/// used across this codebase — does not aim to be exhaustive.
+/// </summary>
+public enum EthernetParameterType
+{
+    GetCurrentIpAddress,
+    GetHostname,
+    GetDomainName,
+    GetLinkStatus,
+    GetCurrentDhcpState,
+    GetCurrentIpMask,
+    GetCurrentRouter,
+    GetMacAddress,
+    GetDnsServer,
+}
+
+/// <summary>
+/// Mirrors Crestron's <c>SocketStatus</c> without requiring the Crestron SDK.
+/// </summary>
+public enum PepperDashSocketStatus
+{
+    SocketNotConnected = 0,
+    SocketConnected = 2,
+    SocketConnectionInProgress = 6,
+    SocketConnectFailed = 11,
+    SocketDisconnecting = 12,
+    SocketBrokenRemotely = 7,
+}