* Revert "Revert "FEATURE: admin/user exports are compressed using the zip format (#7784)""
This reverts commit f89bd55576.
* Replace .tar.zip with .zip
* FEATURE: admin/user exports are compressed using the zip format
* Update translations. Theme exporter now exports .zip file. Theme importer supports .zip and .gz files
* Fix controller test, updated locale and skip saving the csv export to disk
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging