Compute the list of breadcrumbs to show above the collection page.
If the server provides simplified:breadcrumbs tags, those will be used
with the current collection added as the final breadcrumb. Otherwise,
it falls back to OPDS Web Client's breadcrumbs.
Compute the list of breadcrumbs to show above the collection page. If the server provides simplified:breadcrumbs tags, those will be used with the current collection added as the final breadcrumb. Otherwise, it falls back to OPDS Web Client's breadcrumbs.