refactor(core): extract upgrade code paths for improved readability/testing

[joshtrichards]

Summary

The printUpgradePage() function combined upgrade-size detection, app compatibility checks, and view rendering into a single method. This tight coupling made the function harder to understand, maintain, and test.

The function has been refactored to improve clarity and modularity:

• Upgrade size detection:
  • Extracted logic (isInstanceTooBigForWebUpgrade() + reusable helpers for for database queries).
  • Introduced isBigInstanceOverrideRequested() to handle override logic separately.
  • Eliminates duplicate code and streamlines parent function's logic flow.
• App compatibility checks:
  • Extracted logic (prepareUpgradeAppState() + helper to encapsulate exception handling).
  • Makes parent function logic easier to read.
• Other improvements:
  • Replaced magic numbers/strings with named constants for better readability and maintainability.
  • Minimized inline branching and variable clutter.

In addition to clarity, should improve testability going forward.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI