remove template pot and translated po files in the main repo

Since Transifex no longer supports fetching pot file from Github url, we need to submit pot file to Transifex automatically. This PR removes template pot and translated po files and alternatively the resource file(pot file) in Transifex is updated with `make pot` and the translated files(po files) are updated with `make po`. `make pot po` will be run automatically on the nightly build machine.