[ERP5 Master appstore_base] Officejs appstore service worker

Add an appstore service worker at the root url for the apps so they can work offline again. The sw caches the app redirection to its latest version.

• Service worker update relies on the modification date of the app site, which is updated in the software publication workflow when a new app version is accepted.

• This change in CSP was done to make redirect page script work: https://lab.nexedi.com/nexedi/erp5/merge_requests/1512/diffs?commit_id=776266315079cd2266e9a582cd5e263d074b7e6d