feat(tree): typescript/strong typing of nodes

### Feature Description

Currently `*matTreeNodeDef` types the resulting variable as `any`:


### Use Case

>enable you to build web apps with confidence!

The lack of strong typing is really problematic for bigger projects, and it feels like a downgrade in developer experience compared to custom build trees.

Further motivation for this has been described in:

https://github.com/angular/components/issues/16273
https://github.com/angular/angular/issues/28731
https://nartc.me/blog/typed-mat-cell-def/
https://github.com/angular/components/issues/22290

Workaround copied from https://github.com/angular/components/issues/22290:
```ts
import { Directive, input } from '@angular/core';
import { MatTree, MatTreeNodeDef } from '@angular/material/tree';

@Directive({
selector: '[matTreeNodeDef]',
providers: [
{ provide: MatTreeNodeDef, useExisting: TypeSafeMatTreeNodeDefDirective },
],
})
export class TypeSafeMatTreeNodeDefDirective extends MatTreeNodeDef<
NoInfer
> {
readonly matTreeNodeDefTree = input.required>();

static ngTemplateContextGuard(
dir: TypeSafeMatTreeNodeDefDirective,
ctx: any,
): ctx is { $implicit: T; index: number } {
return true;
}
}
```

```diff
-
+
...
-
+
```

Commencez par les points d’entrée MatTreeNodeDef, MatTree et matTreeNodeDef présentés dans l’issue, puis comparez le workaround TypeSafeMatTreeNodeDefDirective lié et les discussions référencées. Le travail est terminé lorsque la variable déclarée par *matTreeNodeDef est fortement typée sans nécessiter le workaround, et que l’utilisation documentée de l’arbre fonctionne toujours.

Rédigé par le modèle d'indexation à partir du texte de l'issue.