Solr 9.6 → 9.7 for integration tests

[thomascorthals]

Three changes to get the integration tests working with Solr 9.7:

• Small change in the schema regarding docValues.
• Returned field order has changed for some queries. Since this field order was actually never guaranteed (we got lucky until now), I've replaced all assertions for document fields with a custom assertDocumentHasFields() method that disregards field order.
• Managed resources still need double percent-encoding, but the way a request fails if you don't apply that workaround has changed.

[thomascorthals]

The release of Solr 8.11.4 requires the same change to the test for the managed resources workaround that was already included in this PR. This actually simplifies things as we no longer need the old version of the test at all now.