[7.111.x] fix: Allow tools running in the terminal to prevent the workspace from stopping due to idling

[vrubezhny]

This adds support for a CLI Watcher in che-machine-exec to prevent DevWorkspace idling when long-running CLI tools are running in the terminal.

The watcher is user-configurable via a '.noidle' YAML file. No admin privileges are required.

How configuration is resolved:

The '.noidle' file is located by searching in the following order:

• A path specified by the CLI_WATCHER_CONFIG environment variable
• Searching upward from the current project directory toward $PROJECTS_ROOT, looking for .noidle
• Falling back to '$HOME/.noidle' (e.g. '~/.noidle')
• If not found, CLI Watcher waits and checks again on the next poll

Example .noidle configuration:

enabled: true
watchedCommands:
  - helm
  - odo
  - sleep
checkPeriodSeconds: 60

Where:

• enabled: Enables or disables the CLI watcher (boolean)
• watchedCommands: List of command names to monitor
• checkPeriodSeconds: Polling interval in seconds (default is 60)

Benefits:

• Works entirely in user space — no container or cluster admin config needed
• Supports live updates (file can be added, edited, or removed while running)
• Helps avoid idle timeout disconnects during long-running CLI workflows
• Allows workspace authors to tailor idle behavior to specific tools

Note: Some processes are always excluded from watching:

• PID 1 (the main container process)
• tail (typically always running in containers)

Issue: eclipse-che/che#23529