feature request: allow running updatecli() with a custom version

[dduportal]

We want to allow specifying a custom version for updatecli, in semantic version format, to allow us earlier testing:

updatecli(action: 'diff', version: '0.92.0`)

If the version attribute is unspecified, we keep the current behavior (e.g. using the updatecli CLI in the provided agent.

Notes:

• Updatecli CLI with specific versions can be downloaded from the GitHub releases: https://github.com/updatecli/updatecli/releases
  • Be careful: releases are prefixed by a v
  • The "RC" versions should be supported (such as https://github.com/updatecli/updatecli/releases/tag/v0.86.0-rc.1)
• If the provided version does not exist, then the call should fail immediately
• The detection of which CLI to use must be done inside the node by autodetecting the OS (Linux, Windows, we do not expect Darwin) and the CPU (amd64, arm64, we do not care about others)