Display connection error message + add detail in output

[sebjulliand]

Changes

The cause of a connection failure was never reported after it happened. This PR fixes this and add the error message in the error notification.

It also adds error details (error JSON representation + stack trace) into the output to help diagnose connection issues.

This should help with #2856 and #2840 .

A new SSH debug output option has been added in the Login settings:

When turned on, it will append SSH debug traces to the Code for i output.

How to test this PR

1. Connect to a system with the wrong address or credentials. Or shut down the SSH server on the LPAR
2. Check out the error notification to see the cause of the issue
3. Check out the Code for IBM i output for error details

Checklist

• have tested my change

[github-actions]

👋 A new build is available for this PR based on dff7073.

• Download here.
• Read more about how to test

[sebjulliand]

Added a new SSH Debug output option in the Login settings:

[worksofliam]

Tried two different scenarios and it works great! This is a nice touch. At first I was confused why it's not a global setting instead of a per-connection, but it does make sense now.

{"errno":-3008,"code":"ENOTFOUND","syscall":"getaddrinfo","hostname":"-xxxx-","vslsStack":[{},{}],"level":"client-socket"}

Error: getaddrinfo ENOTFOUND -xxxx-
    at GetAddrInfoReqWrap.onlookupall [as oncomplete] (node:dns:122:26)
    at GetAddrInfoReqWrap.callbackTrampoline (node:internal/async_hooks:130:17)

[SSH debug] Outbound: Sending CHANNEL_OPEN (r:62, session)
[SSH debug] Inbound: CHANNEL_OPEN_CONFIRMATION (r:62, s:1)
[SSH debug] Outbound: Sending CHANNEL_REQUEST (r:1, exec: cd /home/SNDBX87 ; ls $HOME/.vscode/mapepire-server-2.3.3.jar)

These logs will be very useful in the future, I am sure!

Merge when you're ready 💯

[sebjulliand]

Thanks @worksofliam !

These logs will be very useful in the future, I am sure!

It proved to be useful already 😅: #2840 (comment)