Previously, Angular devtools would mistakenly traverse the same DOM elements multiple times while doing traversal for the component tree explorer. This error case would occur when more than 1 Angular application root component was present on the same page and in distinct DOM branches.
Some example cases that did work previously:
```html
<app-root>
...
</app-root>
```
```html
<app-root>
...
<app-root-2></app-root-2>
...
</app-root>
```
An example of where it would enter the irregular behaviour
```html
<app-root>
...
</app-root>
<app-root-2>
...
</app-root-2>
```
Now, we properly ignore duplicate DOM paths when looking for application and non-application root component to begin the Angular DevTools component discovery logic.
PR Close#62719
The existing DevTools demo app that is used for developing on DevTools is exclusively an NgModule application. This commit creates a copy of the old demo app but with no NgModules and only standalone APIs/Components/Directives/Pipes
PR Close#48533
Previously devtools used a nested workspace for its bazel configurations. This meant framework dependencies were consumed via npm.
Now devtools is part of the root bazel directory that all other files in this codebase fall under. This allows us to build devtools using local angular packages, removing the need to consume these dependencies with npn. This is useful because we no longer have to update these dependencies with an automated tool like renovate, and our CI tests will always run against the most up to date framework packages.
