Fix fleetctl get fleets to use source of truth (DB) for software (#46480)

Resolves #44970 (1/2).

---

- [X] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
- [X] Added/updated automated tests
- [X] QA'd all new/changed functionality manually

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* `fleetctl get fleets` / `get teams` now display software and setup
experience from authoritative software endpoints.
* Preserve literal setup_experience fields (avoid erroneous macos_setup
renames) when applying and when transmitting JSON for software entries.
* **Tests**
* Added regression tests and test helpers to ensure
software/setup_experience are sourced correctly and to prevent nil
panics in related tests.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

changes/44970-fix-apply

@@ -0,0 +1 @@
+* Fixed bug in `apply` to prevent `setup_experience` in software items from being renamed to `macos_setup`.

changes/44970-get-fleets-setup-experience

@@ -0,0 +1 @@
+- Fixed `fleetctl get fleets` (and `fleetctl get teams`) so the software section, including each app's `setup_experience` value, reflects the real configuration instead of being read from the (potentially stale) team config. Software is now fetched from the software titles and setup experience endpoints, which are the source of truth.