ESQL: Unclean generated imports (elastic#127723)

This removes a ton of the tricky juggling we do for generated java files
to keep the imports in order. Instead, we just live with them being out
of order a little. It's not great, but it's so so so much easier than
the terrible juggling we had been doing.

Author: nik9000

x-pack/plugin/esql/build.gradle

@@ -250,6 +250,7 @@ pluginManager.withPlugin('com.diffplug.spotless') {
         "src/main/java/org/elasticsearch/xpack/esql/parser/EsqlBaseParser*.java",
         "src/main/generated/**/*.java",
         "src/main/generated-src/generated/**/*.java"
+      toggleOffOn('begin generated imports', 'end generated imports')
     }
   }
 }

x-pack/plugin/esql/compute/build.gradle

@@ -101,7 +101,7 @@ tasks.named('stringTemplates').configure {
     "",
     "BYTES_REF",
     "org.apache.lucene.util.RamUsageEstimator.NUM_BYTES_OBJECT_REF",
-    "",
+    "BytesRefArray",
     "BytesRefHash"
   )
   var ipProperties = prop("Ip", "BytesRef", "BytesRef", "", "BYTES_REF", "16", "", "")