Unify reviews for Common MB-BB entities

[anshg1214]

This PR unifies reviews for Artist-Author, Work-Literary Work having relationship between them.

[alastair]

A few small improvements that I think we can make on this page.

One thing I was thinking about is that we have relationships in BB pointing to MB ids, but we also have relationships in MB pointing to BB pages. Do you think we should check both of these databases in this method, or should we instead build a report to help editors sync the list between MB and BB?

[alastair]

Just a small thing here, when we know that the "empty" case is an empty list, we don't necessarily need and author_info, because {% for author in author_info %} will be an empty list and won't loop through anything.

However, this being said, I think that we could do this a bit differently:

Suggested change

	{% if author_info is defined and author_info %}
	{% if author_info is defined and author_info %}
	<h4> {{ _('This entity is also in the BookBrainz Database as ') }}
	{% for author in author_info %}

Because if for some reason there are two related authors, we will show this heading twice. We should only do it once.

[github-actions]

Unit Test Results

    1 files  ±0      1 suites  ±0   2m 25s ⏱️ ±0s
201 tests ±0  201 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit c497292. ± Comparison against base commit c497292.