this.path - Get Executing Script's Path

Determine the path of the executing script. Compatible with several popular GUIs: 'Rgui', 'RStudio', 'Positron', 'VSCode', 'Jupyter', 'Emacs', and 'Rscript' (shell). Compatible with several functions and packages: 'source()', 'sys.source()', 'debugSource()' in 'RStudio', 'compiler::loadcmp()', 'utils::Sweave()', 'box::use()', 'knitr::knit()', 'plumber::plumb()', 'shiny::runApp()', 'package:targets', and 'testthat::source_file()'.