test: [Snaps E2E] Test for initial connections

[bowensanders]

Create test for initial connections.

We should update the preinstalled example Snap to use the initialConnections feature to automatically connect with the test-snaps page and then test that we can make requests to the Snap without connecting.

[hjetpoluru]

@FrederikBolding could you provide more information

[Montoya]

The Snap can have endowment:rpc where the permission includes a single origin like the following:

"initialPermissions": {
  "endowment:rpc": {
    "allowedOrigins": [
      "https://metamask.github.io/test-dapp/"
    ]
  }
}

And initialConnections like:

"initialConnections": {
  "https://metamask.github.io/test-dapp/": {}
}

And in the E2E, the dapp calls an RPC method on the Snap and tests to assert that it receives a valid response without having to call wallet_requestSnaps

The Snap still has to be installed before calling the method from the dapp, but this will validate that initialConnections and allowedOrigins still work as expected.

@FrederikBolding can verify if this is the right approach.

[FrederikBolding]

I just updated the description, we can use the preinstalled example Snap for this.