Add Qwen2Moe GGUF loading support (#33264)

* update gguf doc, config and tensor mapping

* add qwen2moe architecture support, GGUFQwen2MoeConverter and q4 unit tests

* apply code style fixes

* reformat files

* assign GGUFQwen2Converter to qwen2_moe

docs/source/en/gguf.md

@@ -78,6 +78,7 @@ For now the supported model architectures are the architectures that have been v
 - LLaMa
 - Mistral
 - Qwen2
+- Qwen2Moe
 
 ## Example usage