Encrypt or Obfuscate cache data in Browser when Javascript SDK use localstorage type

Split SDK Javascript have the option to use the browser Local Storage by setting option "storage.type" to "LOCALSTORAGE", this will store all the SDK cache and allow faster SDK ready time.

However, the cache is stored in plain text, which can be a security issue if there are sensitive information in the whitelists of splits.

It would be better to encode the cache or obfuscate it.