Fix Symfony 7.4 Request::get deprecations in ItemsController

[prateekbhujel]

Summary

Fixes #1282 by replacing deprecated request access in ItemsController.

What changed

• Replaced request()->get('page', 1) with request()->input('page', 1).
• Replaced request()->get('keyword', "") with request()->input('keyword', '').
• Kept page normalization behavior unchanged (< 1 becomes 1).

Why

symfony/http-foundation 7.4 deprecates Request::get() and recommends request source-specific access methods.

Reproduction

1. Use Laravel Filemanager with symfony/http-foundation >= 7.4.
2. Open the file manager item endpoint with a page query (for example: ?page=2).
3. Before this patch, deprecation warnings are triggered from ItemsController due to Request::get() usage.

[prateekbhujel]

I pushed a follow-up update to keep this patch tightly scoped to issue #1282 (just replacing deprecated Request::get() calls in ItemsController).

Also, Scrutinizer is currently reporting Tests: errored on master as well, so that check appears unrelated to this specific change.

[prateekbhujel]

I checked the Scrutinizer failure in detail (inspection 7d68c322-8d33-4803-afc0-310f2a64f9c0). It reports Tests: errored, but this appears to be a repository-wide baseline issue rather than a regression in this patch.

For reference, Scrutinizer is also failed for current master (06483d94-d836-4362-99c3-4e2a25b9bfb8) and multiple recent PR inspections show the same Tests: errored state.

This patch remains intentionally small and scoped to replacing deprecated Request::get() calls in ItemsController.