Can't run Primitive Tests in stand-alone component

### Describe the bug

Part of our setup is to enable us to only load what we need to work on an individual component. If I load the `Primitives` component from the main repo though, I can't perform this workflow, tests won't run independently of the all-up solution we use in the CI for this component.

Related #101

https://github.com/CommunityToolkit/Tooling-Windows-Submodule/issues/62#issuecomment-1588204934

### Steps to reproduce

1. Go to the Primitives component in the Windows repo
2. Open its individual component solution
3. Try and run tests

Can't as Internal UniformGrid helper:
> Test_UniformGrid_FreeSpots.cs(18,20,18,45): error CS0122: 'TakenSpotsReferenceHolder' is inaccessible due to its protection level

If you make that public, then run into issues running the tests due to missing XAML reference (or something) (see image below)

These tests run fine in the CI

### Expected behavior

Able to run tests successfully, just as if run in CI, but just scoped to the component I have open.

### Screenshots


### Code Platform

- [x] UWP
- [x] 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

No, I'm unable to contribute a solution.