Centralize ApplyXamlStyling script

### Describe the bug

Right now we run it from the root, but it lives in the root. Since we have it in tooling now, we should better utilize it.

Not sure how we go about this, probably involves having to tweak the script to look at the CWD vs. where the script is? Not entirely sure of current behavior.

Just noting this as a work item for us to check and then update the dependent repos to use it from tooling vs. copying.

### Steps to reproduce

```text
N/A
```

### Expected behavior

Not copying script file

### 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 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)
- [ ] 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

_No response_

### Help us help you

Yes, but only if others can assist.

Start by locating the ApplyXamlStyling script in the tooling directory and checking how it resolves the current working directory versus its own location. Trace the dependent repositories that copy or invoke it. Done means the script runs from tooling without being copied and the dependent repositories use that shared version.

Scritto dal modello di indicizzazione a partire dal testo della issue.