Modernize Java idioms in WizardNewFolderMainPage

[deepika-u]

This change modernizes a few Java idioms in WizardNewFolderMainPage by:

• Removing redundant return statements.
• Replacing length() > 0 with isEmpty().
• Use pattern matching for instanceof to simplify type checks and eliminate explicit casts.
• Apply minor readability cleanups.

No functional or behavioral changes are intended.

[github-actions]

Test Results

   858 files  ±0     858 suites  ±0   58m 4s ⏱️ - 2m 29s
 8 129 tests ±0   7 886 ✅ ±0  243 💤 ±0  0 ❌ ±0 
20 289 runs  ±0  19 635 ✅ ±0  654 💤 ±0  0 ❌ ±0 

Results for commit 4fa9133. ± Comparison against base commit b5954f1.

♻️ This comment has been updated with latest results.

[deepika-u]

@HeikoKlare - Could you take a look at this when you get some time please?

[BeckerWdf]

change looks good to me

[merks]

In general I think we should do "cleanups" via automated cleanup actions as @laeubi has automated them and not manually like this, because a manual approach looks to be a bottomless pit to me.

[HeikoKlare]

In general, the changes look sound (except for one, where I left a specific comment). But I agree with Ed that investing time into optimizing auto-cleanups than doing manual cleanup would probably be even more valuable (though not all of these changes may be achievable with auto-cleanups).

[deepika-u]

Thanks for the feedback! I agree that automated cleanups are the more scalable approach where applicable. I came across these changes while working on something else, but I'll keep this in mind for similar cleanup work going forward.

[deepika-u]

Please let me know if there's anything else you'd like me to address.

[deepika-u]

@BeckerWdf @HeikoKlare
Please let me know if there's anything else I should address.

[HeikoKlare]

Looks good now, thank you.

[deepika-u]

Looks good now, thank you.

Thanks for your time :)