Add solr-9 compatible images

[tobybellwood]

This PR adds Solr 9 images to lagoon-images.

There are a couple of notable changes from the 8.x images:

• The solr-9-drupal image uses the search_api_solr 4.x branch jump-start directly, instead of a static import
• The location of the docker scripts directory changed, so we introduced a switch to account for it in the custom solr-precreate command
• We now set the SOLR_INSTALL_DIR variable in the drupal image to accommodate the search_api_solr deprecating it from solrcore.properties
• The base image is slightly larger, due to Solr no longer using slim upstream images (confusingly, slim in solr images is now an image without solr modules 🤯

Other than that, the images are virtually identical. However, you may need to reindex or destroy/replace your core to upgrade from solr8 to solr9.

Sample project using this at lagoon-examples/drupal-solr@main...solr9

[bomoko]

Looks good - just one comment, but given I don't see how we get to that issue, it's not a biggy.