#7092364 Add fallback for missing product name in available user licenses dialog

Changes proposed in this Pull Request

This PR adds fallback for the product name displayed in the available license dialog. If you have only one license available and, for some reason, the product name is missing, we should show “product” to communicate meaningful messages to the users.

Testing instructions

Setup

• Download this PR.
• Start both Calypsos with yarn start and yarn start-jetpack-cloud-p (run the last one after the first one is started).
• Go to https://cloud.jetpack.com/pricing.
• Purchase any Jetpack product other than Jetpack Search, and do not activate the product on any site.

Test the existing flows

• Follow the testing instructions here: #59621 to ensure no regression is introduced.

Test missing product name

• To verify if the fallback is working as expected, probably the easiest way would be to simulate these conditions in the code: the hasOneDetachedLicense should have a truthy value, and detachedUserLicense should be set to null.

Screenshots

Before	After

Related to 1201509629272450-as-1201673330627964