Add raw flag to monitor command and implement log formatting for SSE on azd ai agent monitor

[therealjohn]

Prototype for #7209.

Parse SSE/JSON output from monitor and format the results to be more compact and readable.

Include a --raw flag which continues the existing behavior of just printing the raw SSE stream from the server.

[spboyer]

Code Review

1. Default formatting corrupts non-SSE container log lines

azure.ai.agents/internal/cmd/monitor.go:185, monitor_format.go:56 — Medium

The new formatter is applied to every monitor stream when --raw is not set, including the normal container logstream path (--session omitted). formatLine() drops lines starting with event: , strips the data: prefix from data lines, and suppresses blank lines. This means valid application logs like event: user_login, data: payload, or intentional blank separators are no longer shown verbatim.

Fix: Only apply SSE formatting to the session/SSE stream (or gate on response content type). Keep container logstream output raw by default.