[Blazor] Hot reload testing improvements

[javiercn]

We have a long tail of hot reload issues that keep coming back up. As an effort to improve our team velocity we want to invest on some automation that allows us to validate a concrete set of scenarios on a regular basis. The goal of this automation is to act as a canary for when a new issue arises. We will run it on a daily basis as opposed to running it on every CI run.

The general structure for one of these tests is as follows:

• Starts with a pre-configured existing project.
• Runs dotnet watch or equivalent gesture.
• Loads a page in the browser using Playwright.
• Programmatically applies a change to one or more files (add a file, remove a file, edit its contents).
• Perform any action if needed (like instructing the browser to navigate to a new location)
• Validates that the changes have taken effect.

The list of scenarios is something that we will define, but includes things like:

• Adding a new component
• Adding a parameter to an existing component.
• Modifying the generated UI code.