Bug 36723: Add musical presentation to Elasticsearch index mappings

Testing plan:

1. Start up KTD with Elasticsearch: ktd --es8 up
2. Apply the patch and restart everything (restart_all).
3. Reset the mappings: Administration > Catalog > Search engine configuration (Elasticsearch) > Reset mappings (at the bottom of the page)
4. Reindex: koha-elasticsearch --rebuild -d -b -a kohadev
5. Alternative to steps 3 and 4: reset_all
6. Update the visibility for 254$a in the default framework so that it is visible in the Editor (OPAC, Staff interface should already be selected).
7. Add a new record using the default framework and put a term in 254$a, such as 'Full score'.

Sponsored-by: Education Services Australia SCIS
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>

admin/searchengine/elasticsearch/mappings.yaml

@@ -2731,6 +2731,18 @@ biblios:
     opac: 1
     staff_client: 1
     type: ''
+  musical-presentation:
+    label: musical-presentation
+    mandatory: ~
+    mappings:
+    - facet: ''
+      marc_field: '254'
+      marc_type: marc21
+      sort: 1
+      suggestible: ''
+    opac: 1
+    staff_client: 1
+    type: ''
   nal-call-number:
     label: nal-call-number
     mandatory: ~