Add V2G Transfer Protocol decoder/encoder

Implements C# console application for decoding ISO 15118-2, DIN SPEC 70121, and SAP protocol messages from binary data. Features include:
- V2G Transfer Protocol header parsing
- EXI, DIN, and SAP message type support
- Network packet analysis (Ethernet/IPv6/TCP)
- Hex dump utilities
- Raw data parsing from hex files
- Sample raw data for testing

Successfully tested with sample V2G EXI message data.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

V2GProtocol.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>V2GDecoder</AssemblyName>
+  </PropertyGroup>
+
+</Project>