[WIP] Misc fixes and improvements

[cezarBD]

This work has been done as part of @BeDefended.

This is an attempt to revive the project by fixing a few known issues. Summary of updates:

• The missing env vars are added from Is there a dev.env template missing? #36 (comment).
• Fixed local storage for screenshots, similar to Update api.js and docker-compose.yml #47 (comment).
• The google OAuth was disabled to make it easier to deploy this in a single user scenario with no need to rely on a google account. Just click on login button and the session will be automatically created.
• Due to the previous point, the admin control panel and the public XSS API are now running on separate ports, so that it's possible to firewall the control panel off.
• The new env file to edit is .env and is, as such, hidden.

Known bugs:

• The login page is still present, even though it's not needed now.
• The URL from the payload generator is missing the right port / hostname at the moment, but it is enough to edit it manually to point to the right location.
• HTTPS and public deployment have not been fully tested yet.