Improve query speed for IslandoraUtils::getTermForUri()

[joecorall]

Continuation of #997
Closes Islandora/documentation#2272

What does this Pull Request do?

Improve performance for IslandoraUtils::getTermForUri(). Sets the new approach as the default, allowing sites to revert to the current, single query approach with a config checkbox in Islandora settings.

How should this be tested?

Made a simple drush script

$ cat << EOF > scripts/1067.php
<?php

\$i = 0;
while (++\$i < 100) {
  \$term = \Drupal::service('islandora.utils')->getTermForUri("http://purl.org/coar/resource_type/c_18cc");
}
EOF

Then ran it and it took 17s to complete

$ time drush scr scripts/1067.php 
real    0m 17.46s
user    0m 0.52s
sys     0m 0.38s

Applied this PR and ran again and execution dropped to 1s

$ cd path/to/drupal/root
$ jq '.extra.patches."drupal/islandora" += {"Speed up getTermForUri": "https://github.com/Islandora/islandora/pull/1067.patch"}' composer.json > composer.json.tmp
$ mv composer.json.tmp composer.json
$ composer install
$ drush updb -y
$ time drush scr scripts/1067.php 
real    0m 0.99s
user    0m 0.46s
sys     0m 0.18s

It's definitely the query here causing the slowdown, as if I replace the query with $results = [12]; I get similar 1s executions.

Here's the query that entityTypeManager is running:

SELECT t.revision_id, tid FROM taxonomy_term_data t
LEFT JOIN taxonomy_term__field_authority_link a ON a.entity_id = t.tid
LEFT JOIN taxonomy_term__field_external_uri e ON e.entity_id = t.tid
WHERE (a.field_authority_link_uri = 'http://purl.org/coar/resource_type/c_18cc') or (e.field_external_uri_uri = 'http://purl.org/coar/resource_type/c_18cc')

I think due to the orGroup this is slowing down these queries. It appears be more efficient to run several queries.

Documentation Status

• Does this change existing behaviour that's currently documented?
• Does this change require new pages or sections of documentation?
• Who does this need to be documented for?
• Associated documentation pull request(s): ___ or documentation issue ___

Additional Notes:

Any additional information that you think would be helpful when reviewing this
PR.

Interested parties

Tag (@ mention) interested parties or, if unsure, @Islandora/committers

[rbos]

Can attest that this patch seems to improve general site responsiveness. Large collections load much faster.