[amp story shopping] Re-show / keep displaying shopping tags when attachment is open

### Description

Currently the shopping tags animate out after 5 seconds and remain faded out.

When the shopping attachment is opened, show the tags and keep them on screen.
When the attachment closes keep the tags on screen then animate them out after 5 seconds.

Doing this will help the user discover the other shopping tags on the page.

### Alternatives Considered

We could not animate out the tags and leave them on screen.
This potentially blocks content on the page.