Is there a git command to revert all uncommitted changes in a working tree and index and to also remove newly created files and folders?
Please note that there might still be files that won't seem to disappear - they might be unedited, but git might have marked them as being edited because of CRLF / LF changes. See if you've made some changes in .gitattributes recently.
In my case I've added CRLF settings into the .gitattributes file and all the files remained in the "modified files" list because of this. Changing the .gitattributes settings made them disappear.