Created by: tysongach
aria-labelledby accepts ids of other elements which act as an
accessible label(s). It's great for providing a label to tables, which
are large amounts of content; it helps people understand what the
table content actually is.
We're currently using aria-labelledby on tables in Administrate,
pointing to the id of the h1 on index pages. However, this breaks
when tables are shown as attribute data on show pages, because the id
of page-title does not exist, and it also is not the proper label for
the table (the attribute name is). You can see an example of this here:
https://administrate-prototype.herokuapp.com/admin/customers/9849
This PR allows an id of an element to be passed into the partial
which displays the collection table, so that it can used as the value
for the table's aria-labelledby attribute.