SOLR-8127 Distributed Luke (#4149)

* Fans out to one replica per shard by default when in Solr Cloud mode as well as with `shards` explicitly specified in non-Cloud mode
* Any index information that can't be aggregated, i.e. directory, version, indexCommit, etc., will be placed for every *responding* shard in a new shards response field. This only gets returned when shards.info=true
* docs and docCount were widened to long as they can now overflow. For javabin codec compatibility the server will narrow these to int for old calling SolrClients (when it is safe to do so)
* Previously show=doc mode would error if it couldn't find a matching doc but now returns an empty response and a 200 status code
* show=doc in distributed mode works only with Solr document Id but not with lucene docId, i.e. "id=..." works but "docId=..." does not.
* When in distributed mode Luke handler will validate index and schema flags of each field for consistency and error with an informative message in case of any mismatch.
* You can go back to the old, non-distributed behavior in Cloud mode by specifying distrib=false
* For single-sharded Solr Clouds there is no behavior change (this is a special case).

Co-authored-by: David Smiley <dsmiley@apache.org>

Author: kotman12

changelog/unreleased/SOLR-8127-distributed-luke.yml

@@ -0,0 +1,8 @@
+# See https://github.com/apache/solr/blob/main/dev-docs/changelog.adoc
+title: Luke handler now aggregates results across multiple shards and does this by default in SolrCloud mode.
+type: added # added, changed, fixed, deprecated, removed, dependency_update, security, other
+authors:
+  - name: Luke Kot-Zaniewski
+links:
+  name: SOLR-8127
+  url: https://issues.apache.org/jira/browse/SOLR-8127