FR | Add an ability to create a watchPath to become compliant before moving from the 'getting ready' screen, into the progress screen

[philipross]

There's a few threads on the macadmins Slack, Jamf-Setup-Manager channel about using a custom, locally installed icon as the AppIcon.
Seemingly there's been some changes that now limit the control of the install order when installing during pre-stage, which make it trickier to achieve this and can often result in a brok en icon image.

This FR is a request to add a watch path that can be configured to wait as part of the initial 6(?) actions on the 'Getting Ready' screen, before the progress screen starts to run through the setup items.
That way we could configure it to be the image path (or something else) and whilst Setup Manager would be running, it wouldn't progress past the initial 'getting ready' screen before that watch path is compliant.

Discussed on this slack thread:
https://macadmins.slack.com/archives/C078DDLKRDW/p1736768761947619

[scriptingosx]

In 1.2, the image loading will be more resilient and wait for up to 15 seconds (the exact time period might still be changed) to see if an image becomes available.

This request is for different behavior, as in: Setup Manager should wait until the resources are available or other wise ensure the resources are available before moving on to a screen that shows them