[Converters] Static converter interface for x:Bind

### Describe the bug

Very often binding requires a small, rather trivial, function... So trivial that if it weren't needed in XAML it would just be inline code.

Converters exist to bridge this gap, but using a full converter instance can be unnecessarily heavy when using x:Bind, which allows function binding.

My proposal is to introduce public static methods that provide the actual, strongly-type, conversion function into all of the toolkit converters.

### Steps to reproduce

```text
N/A
```

### Expected behavior

This:
```xml

...

```

Could be replaced with this:
```xml

```

### Screenshots

_No response_

### Code Platform

- [ ] UWP
- [ ] WinAppSDK / WinUI 3
- [ ] Web Assembly (WASM)
- [ ] Android
- [ ] iOS
- [ ] MacOS
- [ ] Linux / GTK

### Windows Build Number

- [ ] Windows 10 1809 (Build 17763)
- [ ] Windows 10 1903 (Build 18362)
- [ ] Windows 10 1909 (Build 18363)
- [ ] Windows 10 2004 (Build 19041)
- [ ] Windows 10 20H2 (Build 19042)
- [ ] Windows 10 21H1 (Build 19043)
- [ ] Windows 10 21H2 (Build 19044)
- [ ] Windows 10 22H2 (Build 19045)
- [ ] Windows 11 21H2 (Build 22000)
- [ ] Other (specify)

### Other Windows Build number

_No response_

### App minimum and target SDK version

- [ ] Windows 10, version 1809 (Build 17763)
- [ ] Windows 10, version 1903 (Build 18362)
- [ ] Windows 10, version 1909 (Build 18363)
- [ ] Windows 10, version 2004 (Build 19041)
- [ ] Windows 10, version 2104 (Build 20348)
- [ ] Windows 11, version 22H2 (Build 22000)
- [ ] Other (specify)

### Other SDK version

_No response_

### Visual Studio Version

_No response_

### Visual Studio Build Number

_No response_

### Device form factor

_No response_

### Additional context

BindBack will not be usable because it does not return an actual value and is basically just a function that runs when the dependency property is updated.

### Help us help you

Yes, I'd like to be assigned to work on this item.