GDT-211-publishers-mapping

Why these changes are being introduced:
* Implement ADR # 3 for timdex-index-manager after transmogrifier has been updated

How this addresses that need:
* Add publishers field to opensearch_mappings.json
* Remove publication_information field

Side effects of this change:
* Reindexing required for new field mapping

Relevant ticket(s):
* https://mitlibraries.atlassian.net/browse/GDT-211

config/opensearch_mappings.json

@@ -315,8 +315,28 @@
           }
         }
       },
-      "publication_information": {
-        "type": "text"
+      "publishers": {
+        "type": "nested",
+        "include_in_parent": "true",
+        "properties": {
+          "name": {
+            "type": "text",
+            "fields": {
+              "keyword": {
+                "type": "keyword",
+                "normalizer": "lowercase"
+              }
+            }
+          },
+          "date": {
+            "type": "keyword",
+            "normalizer": "lowercase"
+          },
+          "location": {
+            "type": "keyword",
+            "normalizer": "lowercase"
+          }
+        }
       },
       "related_items": {
         "type": "nested",