Update ABOUT files

[chinyeungli]

Following are some of the samples that the ABOUT files are still using "dje_license", these should be updated to use the "license_expression":

https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/formattedcode/templates/html-app/assets/DataTables.ABOUT
https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/formattedcode/templates/html-app/assets/bootstrap-fonts.ABOUT
https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/formattedcode/templates/html-app/assets/jquery.ABOUT
https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/formattedcode/templates/html-app/assets/jstree.ABOUT
https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/formattedcode/templates/html-app/assets/respond.ABOUT

In addition, we want to create package_url field in ABOUT files if appropriate.
Since we don't have "partial package concept" (i.e. code borrow elsewhere and modified), we shouldn't use "package_url" in this context to avoid confusion.