[UNSTABLE] add `variable_declaration` node and `ANY_VARIABLE` type
[UNSTABLE] add `variable_declaration` node and `ANY_VARIABLE` type

RickCarlino/farmbot-web-app,FarmBot/Farmbot-Web-API,FarmBot/Farmbot-Web-API,gabrielburnworth/Farmbot-Web-App,RickCarlino/farmbot-web-app,FarmBot/farmbot-web-app,FarmBot/Farmbot-Web-API,FarmBot/Farmbot-Web-API,gabrielburnworth/Farmbot-Web-App,gabrielburnworth/Farmbot-Web-App,RickCarlino/farmbot-web-app,FarmBot/farmbot-web-app,FarmBot/farmbot-web-app,RickCarlino/farmbot-web-app,RickCarlino/farmbot-web-app,FarmBot/Farmbot-Web-API,gabrielburnworth/Farmbot-Web-App,gabrielburnworth/Farmbot-Web-App