Add 'tctl autoupdate agents status'

[hugoShaka]

This PR implements tctl autoupdate agents status.

Part of: RFD-184

Goal (internal): https://github.com/gravitational/cloud/issues/10289

This PR contains the following changes:

• rename internal tctl client tool update variables and functions to scope them for tools and leave room for agents (e.g. targetCmd -> toolsTargetCmd)
• add autoupdate_agent_rollout read-only reight to the editor preset
• add tctl autoupdate agents status command

Example output:

$ ./tctl autoupdate agents status
Agent autoupdate mode: enabled
Rollout creation date: 2025-01-14 16:17:36
Start version: 17.0.1
Target version: 17.1.5
Rollout state: Done

Group Name State Start Time          State Reason
---------- ----- ------------------- --------------
dev        Done  2025-01-15 12:00:08 outside_window
stage      Done  2025-01-15 16:17:45 outside_window
prod       Done  2025-01-15 18:00:12 outside_window
backup     Done  2025-01-14 20:00:31 outside_window

[vapopov]

LGTM