Code Quality: Move some ViewModel classes into the appropriate namespaces

[0x5bfa]

Description

The first step to clean up ViewModels.

Motivation and Context

PR Checklist

• Were these changes approved in an issue or discussion with the project maintainers? In order to prevent extra work, feature requests and changes to the codebase must be approved before the pull request will be reviewed. This prevents extra work for the contributors and maintainers.
  Related Code Quality: Continued work to clean up entire project #12340
• Did you build the app and test your changes?
• Did you check for accessibility? You can use Accessibility Insights for this.
• Did you remove any strings from the en-us resource file?
  • Did you search the solution to see if the string is still being used?
• Did you implement any design changes to an existing feature?
  • Was this change approved?
• Are there any other steps that were used to validate these changes?

Screenshots

None

[ferrariofilippo]

Nothing seems to miss, but still there are some style-related changes that you should consider

[0x5bfa]

@ferrariofilippo I'm currently working on step 1 in #12340. All of them are out of scope of the PR.

1. Rename files with the appropriate name and put them into appropriate namespace for each.
2. Rename variables with preferred name to follow the guideline (The most likely to happen is that I rename property-backing-field from '_isHidden' to '_IsHidden')
3. Reorder variables & methods to follow the class structure guideline (Section 3 in the guildeline)
4. Refactor to improve performance. You can see what I will work on in Requirements section.

[0x5bfa]

@ferrariofilippo But thank you always for reviewing my refactoring PR. I will refer to those reviews in the further PR.

@yaira2 Ready for review.

[ferrariofilippo]

I checked it again and nothing is missing, so LGTM!
I found another couple of things that you may change in phase 2:

• At src/Files.App/ViewModels/UserControls/StatusCenterViewModel.cs CloseBanner(), it might be better to use IndexOf and then RemoveAt to avoid comparing all the elements twice
• At src/Files.App/Data/Items/StatusBanner.cs StatusBanner(), line 85, it might be better to use a swtch assing like: Title = Operation switch ...

[yaira2]

I checked it again and nothing is missing, so LGTM!

Thanks! Can I resolve the conversations?

[ferrariofilippo]

Yes