Add new Tor Browser translation files to Transifex

Tor Browser is changing their translation files, so we are going to have new files to translate in Transifex. The strings for translation will remain mostly the same, only the format changes.

The TB devs want the new resources to appear all in the same translation branch.

The files are already on the transifex Sandbox, and will not have a git URI to update automatically for now.

Files:

• https://www.transifex.com/otf/tor-project-sandbox/newidentityproperties/ - the button on the addressbar
• https://www.transifex.com/otf/tor-project-sandbox/securitylevelproperties/

This files will have a branch called base-browser in the translation.git repo