Generate nsxtool resources (instruments + databases) as cpp code

It is important to insure that nsxtool always find its necessary resources to work correctly. Generating resources files as cpp code during cmake process will allow this. In doing so, the first time a given resource is asked, the one stored in the cpp file will be fetched and saved as a YAML file on a predefined destination ($HOME/.nsxtool on macos and $APPDATA/nsxtool on windows). This mechanism will also allow to provide dmg installers that will not have to install resources as files during the drag and drop process.