refactor(console): register commands by state and simplify CLI command-loading

[joshtrichards]

• Resolves: #

Summary

What

• Register only the commands that are valid for the current global state (installed / uninstalled / maintenance / upgrade-needed).
• Move early CLI environment validation into Application::checkEnvironmentEssentials() and run OC_Util::checkServer(...) before loading apps.
• Simplify core/register_command.php with explicit per-state command lists and reduced boilerplate.
• Explicit command lists for each state in core/register_command.php.
• Simpler, clearer control flow in Application.php.
• Miscellaneous robustness/UX improvements in Application.php

Why

• Fail fast: avoid loading many apps when the PHP/environment is clearly unsuitable.
• UX: administrators only see commands that actually work in the current server state.
• Safety: reduces accidental invocations of commands that would be unsafe in the current state.
• Maintainability: clearer control flow. delegation of details to private functions, and explicit command lists make it easier to reason about code

TODO

• ...

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)