Check if rapidpe p-astro is public before including in alerts

There have been a few instances of the rapidpe p-astro needing to be removed from the public eye before we send an initial notice. At the moment, that means that both the public and the p_astro tags need to be removed. Removing the latter tag makes it not visible in the p-astro section of the superevent, even for those signed in with LVK credentials. Ideally, it would still be displayed there, and ideally we'd only need to remove one tag to stop the file from being used in public alerts.

This MR also slightly changes the code that grabs the pipeline p-astro file to make it the same as the other code that checks for a public + one other tag. It also makes the style uniform between the two p-astro files.