Bug 22246: Fix indexing of large fields with Elasticsearch

Bug 22246: Fix indexing of large fields with Elasticsearch

Deduplicate multivalued fields and make sure sort fields are not excessively long. Also updates default mappings so that sort fields are not created for item fields where it doesn't make sense.

Test plan:
1. Reset ES mappings in administration
2. Check that sort is '0' for local-classification in biblio mappings.
3. Change sort back to '1' for local-classification for the next steps.
4. Create a record with 20 items, each with a 100 character long call number
5. Check that when indexed, the record in ES does not have duplicates in any of the item fields and local-classification__sort is truncated to 255 characters.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>