feat: expose call outcome on call_log messages

[alpersamur3]

What

Exposes the outcome of call_log messages on the Message structure: message.callOutcome, message.callDuration and message.isVideoCall.

Why

There was no way to tell how a call ended. In particular, when an incoming call is answered on one of the account's other linked devices, callOutcome is 'AcceptedElsewhere', which lets a bot know it should not auto-answer. Other common values include 'Completed', 'Missed', 'Rejected', 'Cancelled' and 'Failed'.

Requested in the call PR discussion (#201825).

How

call_log messages already carry the outcome in their serialized model; this just surfaces it (along with the duration and the video flag) on the Message structure. call_log messages are delivered through the existing message / message_create events, so no new event is needed.

Usage

client.on('message', (msg) => {
    if (msg.type === 'call_log' && msg.callOutcome === 'AcceptedElsewhere') {
        // The call was answered on another linked device
    }
});

Tested

• Verified against a live session: an incoming call answered on another device produced a call_log message with callOutcome: 'AcceptedElsewhere'; a normal completed call read 'Completed'.
• Unit tests added in tests/callLog.js.

[alpersamur3]

Re-checked against the current WA Web (2.3000.1048354754): call_log messages still carry callOutcome, callDuration and isVideoCall, so this is still good to go.

@BenyFilho @tuyuribr @aliyss this one is small and independent of the other call PRs, if you have a moment to review it.