As a user, I want to see a list of currently installed OLM v1 operators. In the left nav, there should be a new nav item under the Ecosystem section called "Installed Extensions", which will lead to the new ClusterExtensions list page.

AC:

• new "Installed Extensions" nav item under the Ecosystem section leads to a list page for the ClusterExtension resource kind
• default list page is used
• This should be implemented as a dynamic plugin extension
• Add an e2e test covering the new list page

Non-goals:

• custom list page will be implemented as a future story