Related to no issue.

This PR makes the code more cleaner and make it compliant for packaging.

"Quick" note on what changed:

• Include need to be prefixed by the path after src. E.g.: the file src/core/Core.hpp needs to be included as #include "core/Core.hpp" or src/resource/window/Window.hpp as #include "resource/window/Window.hpp"
• No multiple add_includedirs because we want to use include like in package, so one at the root of the plugin/util. That's the reason why we now needs to include the path after src folder.
• Now, a lot of add_headerfiles are added to sync local build and package build. So to include a file in a new folder of plugin/util you need to add something like add_headerfiles("src/(the/path/of/the/file/*.hpp)") (don't forget .inl too)
• I removed some stuff of plugin/utils/core targets because it was already defined in root xmake like set_policy, add_rules, add_requires (important)
• I added some stuff a the root xmake like set_languages("c++20"), set_warnings("allextra") (this will uniform warnings along all target), add_rules("plugin.compile_commands.autoupdate", {outputdir = ".vscode"}) (each times you will try to compile, it will generate a compile_commands.json, useful for linter)
• I added some nano features: InputManager::IsKeyPressed, Window::SetResizable
• I removed some useless attributes: m_lastDesired or _decoder