Support multi-value search for existing fields

[timrobertson100]

The fields listed below are in ES and treated as single value strings.
Without breaking any pubic APIs, we can provide better search by treating them as multi-value fields.

For example, consider a record arriving with recordedBy: Morten Hoefft | Tim Robertson.
It is not possible today, to search for Tim Robertson and discover this record, along with others having this value. See also #178

Terms that currently support auto-suggest are noted, which may bring additional considerations.

Term	Auto-suggest
datasetID
datasetName	yes (to be added)
otherCatalogNumbers	yes (to be added)
typeStatus
recordedBy	yes
identifiedBy	yes
preparations
samplingProtocol	yes

This issue is intended to focus only on existing fields in ES, and those already being added in work in progress, and not to propose additional fields.

[MortenHofft]

It believe it would be an appreciated feature if ordering could be retained (when serialized back into a string).

Perhaps related: gbif/portal-feedback#3292 (comment) for the desire to keep ordering in the multimedia array.

[marcos-lg]

Deployed to PROD