Add WebApp management in firebase-admin/project-management

[opack]

Is your feature request related to a problem? Please describe. I want to totally create my Firebase infrastructure using code. Unfortunately, I cannot create web apps using firebase-admin/project-management; only Android and iOS apps are available.

Describe the solution you'd like Methods in ProjectManagement to handle WebApps, same as Android and iOS apps.

Describe alternatives you've considered Extending the ProjectManagement object by myself, adding the methods after copying what's done for Android. But there are a couple of problems and it's not really efficient.

Additional context None

[google-oss-bot]

I found a few problems with this issue:

• I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.
• This issue does not seem to follow the issue template. Make sure you provide all the required information.