Support connecting to ROS using a self-signed certificate

[kraenhansen]

Because chromes native fetch API does not trust self-signed certificates, Studio is unable to use Realm JS to authenticate with ROS if it's using an untrusted self-signed certificate.

This is blocked by realm/realm-js#1464.

Alternatively, this issue could be fixed by implementing authentication, using a different HTTPs client (possibly node-fetch - which Realm JS actually also uses if fetch is not available natively) to issue the requests with an agent that does not validate certificates or trusts this particular untrusted certificate.

[kraenhansen]

@kneth pointed me in a direction that unblocked me from realm/realm-js#1464