refactor: Add external LLMCore lib (#334)

* feat: Add LLMCore submodule

pluginllmcore/CMakeLists.txt

@@ -0,0 +1,35 @@
+add_library(PluginLLMCore STATIC
+    RequestType.hpp
+    Provider.hpp Provider.cpp
+    ProvidersManager.hpp ProvidersManager.cpp
+    ContextData.hpp
+    IPromptProvider.hpp
+    IProviderRegistry.hpp
+    PromptProviderChat.hpp
+    PromptProviderFim.hpp
+    PromptTemplate.hpp
+    PromptTemplateManager.hpp PromptTemplateManager.cpp
+    RequestConfig.hpp
+    ProviderID.hpp
+    HttpClient.hpp HttpClient.cpp
+    DataBuffers.hpp
+    SSEBuffer.hpp SSEBuffer.cpp
+    BaseTool.hpp BaseTool.cpp
+    ContentBlocks.hpp
+    RulesLoader.hpp RulesLoader.cpp
+    ResponseCleaner.hpp
+)
+
+target_link_libraries(PluginLLMCore
+    PUBLIC
+    Qt::Core
+    Qt::Network
+    QtCreator::Core
+    QtCreator::Utils
+    QtCreator::ExtensionSystem
+    LLMCore
+    PRIVATE
+    QodeAssistLogger
+)
+
+target_include_directories(PluginLLMCore PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})