Web text content hidden from user in page is visible in Hypothesis sidebar

Per user report https://app.hubspot.com/contacts/6291320/ticket/448202145/

While annotating a page at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4384082 the user noticed that the text displayed in the Hypothesis sidebar did not match the selected on the page.


By looking at the HTML we can see that there is content on the page which is styled as `display:none`, so as not to be visible to a reader. Here is an example element from that page:
`{"type":"entrez-nucleotide","attrs":{"text":"JX501334","term_id":"961791677","term_text":"JX501334"}}JX501334`

However, when this text is selected for annotation Hypothesis shows all the content selected, regardless of its styled visibility.

This is unexpected to a user, and can be confusing or appear that there is something wrong.

Further internal discussion https://hypothes-is.slack.com/archives/C2BLQDKHA/p1623787905253900

Reproduce the report on the NCBI page linked in the issue and inspect the provided display:none HTML example during text selection. Trace the annotation selection behavior from the affected page and verify that hidden text is excluded from the sidebar while visible selected text remains available.

Written by the indexing model from the issue text.