Port Converters

## TODO

```[tasklist]
### Base Porting Checklist
- [x] Update namespace (to `CommunityToolkit.WinUI.Converters`)
- [ ] Merge differences from UWP main to WinAppSDK, Uno Platform fork
- [x] Import original doc or setup new doc
- [ ] Needs a refresh/update, and probably split
- [ ] https://github.com/CommunityToolkit/Windows/issues/133
- [ ] Brought over existing unit tests from main repo (**did not** compare or merge with WinUI branch **nor** update to use our helpers)
- [x] All brought over tests pass for UWP/WinAppSDK
- [ ] https://github.com/CommunityToolkit/Windows/issues/132
- [ ] Support for WASM via Uno Platform (Had trouble testing due to https://github.com/CommunityToolkit/Tooling-Windows-Submodule/issues/24)
- [ ] ResourceNameToResourceStringConverter definitely needs to be compared
- [x] `StringFormatConverter` from first sample worked fine!
```

```[tasklist]
## Converters
- [x] BoolNegationConverter
- [x] BoolToObjectConverter
- [x] BoolToVisibilityConverter
- [x] CollectionVisibilityConverter
- [x] ColorToDisplayNameConverter
- [x] DoubleToObjectConverter
- [x] DoubleToVisibilityConverter
- [x] EmptyCollectionToObjectConverter
- [x] EmptyObjectToObjectConverter
- [x] EmptyStringToObjectConverter
- [x] FileSizeToFriendlyStringConverter
- [x] FormatStringConverter
- [x] ResourceNameTOResourceStringConverter
- [x] StringFormatConverter
- [x] StringVisibilityConverter
- [x] TaskResultConverter
- [x] TypeToObjectConverter
- [x] VisibilityToBoolConverter
```

## Notable Changes

- Changed `FormatStringConverter` to `IFormattableToStringConverter` to differentiate from `StringFormatConverter` (too confusing to have such a similar name)

```[tasklist]
## Prerequisites
- [ ] https://github.com/microsoft/microsoft-ui-xaml/issues/8287
```

```[tasklist]
## Future Improvements
- [ ] P2: Central x:Bind helper class that leverages shared logic of converters?
```

Start by comparing the existing UWP main and WinUI branch implementations with the Uno Platform fork under the CommunityToolkit.WinUI.Converters namespace. Review the brought-over unit tests and the linked issues, especially for ResourceNameToResourceStringConverter and WASM support. Done means the outstanding checklist items are resolved and the converter tests pass across the supported targets.

Written by the indexing model from the issue text.