Add missing tests and finish some actions related to Solr 9 deployment

[ffont]

This is a list of things remaining to be done in relation to the Solr9 deployment:

• Add test for get_stream_sounds (which also performs a search in solr) and refactor some parts of it if needed
• add a test in test_search_engine_backend scripts to test multiple-word queries.
• Integrate alastair's local solr comparison script into search engine tests (combination of query + filter, including multiple filters and examples with OR on a filter)
• add a test in test_search_engine_backend for geo queries
• Add tests on date facet
• handle difference between datepoint and daterange (created)
• Add improvements in solr deployment workflow so we don't have duplicated schema files (in freesound and freesound-deploy repository) and we generally facilitate solr deployment steps
• Update index management commands to report progress, instead of "INFO # Adding 4000 sounds to the search engine", report "Adding 64000/615561 sounds to the search engine"
• Remove old solr 5 configuration and code from freesound
• Upgrade to solr 9.4
• Update dev docker-compose settings to remove solr5, and rename solr9 service to "search"
• Add a Configuration option to index management commands to specify either a backend to use for the command, or allow a custom core name or solr endpoint to perform the operation on

[ffont]

@alastair this "handle difference between datepoint and daterange (created)" is done right?

[alastair]

We launched solr9 on prod and tested datepoint+daterange, and it works as expected