strip_html should leave space between block elements

[dfdan]

Package version (if known): all

Describe the bug

When strip_html is passed string containing multiple paragaphs (eg by rdm-records' ui serialiser), entries with multiple paragraphs are concatenated without spacing. This looks poor and reduces readability.

Steps to Reproduce

See screenshots below (from Invenio RDM), or:

In [3]: strip_html('<p>a</p><p>b</p>')
Out[3]: 'ab'

Expected behaviour

A single space should be inserted between the paragraphs content to ensure the stripped description is readable, ie:

In [3]: strip_html('<p>a</p><p>b</p>')
Out[3]: 'a b'

Screenshots (if applicable)

Invenio RDM record description with 2 paragraphs:

Renders in search without space between paragraphs:

Additional context

I have made a local workaround that inserts a space after any paragraph closing tag before calling strip_html. Perhaps
a proper fix would use html.parse to pass the description to strip_html 1 paragraph at a time? Happy to give that a go if it seems sensible.

[dfdan]

I've looked into this further - there is a known issue with bleach addressed by this PR: mozilla/bleach#642

I've confirmed this fixes the issue, so we can just bump dependencies here if/when that PR merges.

[lnielsen]

Ok, then I'm closing the ticket since we'll get it in automatically with the latest bleach.