Enhancement: Don't display the stripe warning in the inserter

### Impacted plugin

Jetpack

### What

The pattern/block inserter displays an admin-only message for connecting to stripe:

### How

Ideally this would only display in the editor canvas itself, not in the previews. It's only a temporary situation - an unfair preview, and in any case website viewers wouldn't see it.

Start by tracing the pattern/block inserter and the Stripe connection warning in the Jetpack codebase, comparing how the editor canvas and previews render the message. Done means the warning is absent from inserter previews but remains visible in the editor canvas.

Written by the indexing model from the issue text.