Search by different fields

[Piakret]

We would like the following fields to be searchable in the repository:

• doi
• author
• title
• identifier like ORCiD or ror

and if possible the search for exact values by using quotes ("...")

We need also to be able to do a query excluding a few terms in the title.
The query works like this in the current repository:
NOT addendum NOT erratum NOT corrigendum NOT editorial NOT obituary
(This is the only use case, but we need to be able to do this filtering)

@agentilb @pamfilos