Support connection to aepp opened over file:/// protocol

[davidyuk]

on sdk side it was implemented in https://github.com/aeternity/aepp-sdk-js/pull/1900

Opening over file:// needed for fresh developers or to run something super decentralized. I consider this not an important case.

Steps to implement:

• update SDK (not released yet);
• update your content script with 'null' check;
• add file:///* to your webmanifest;
• ensure that SW works with the reproduction.

All needed materials you can find in the abore PR.

[davidyuk]

https://github.com/aeternity/aepp-sdk-js/releases/tag/v13.2.2 🎉