Allow multiple values in the resource-type-id parameter

[digitaldogsbody]

Purpose

We allow querying against multiple values for resourceType, but not resourceTypeGeneral. Since resourceTypeGeneral is a controlled list, it seems useful to allow multiple queries in a single API call, as this uses the much more efficient filter approach in ES (vs doing ?query=types.resourceTypeGeneral:x OR types.resourceTypeGeneral:y)

This PR adds support for multiple values in the resource_type_id parameter, which ultimately uses the value from resourceTypeGeneral via https://github.com/datacite/lupo/blob/master/app/models/doi.rb#L1232-L1237 and https://github.com/datacite/lupo/blob/master/app/models/doi.rb#L2489-L2495

closes: Add github issue that originated this PR

Approach

Open Questions and Pre-Merge TODOs

Learning

Types of changes

• Bug fix (non-breaking change which fixes an issue)

• New feature (non-breaking change which adds functionality)

• Breaking change (fix or feature that would cause existing functionality to change)

Reviewer, please remember our guidelines:

• Be humble in the language and feedback you give, ask don't tell.
• Consider using positive language as opposed to neutral when offering feedback. This is to avoid the negative bias that can occur with neutral language appearing negative.
• Offer suggestions on how to improve code e.g. simplification or expanding clarity.
• Ensure you give reasons for the changes you are proposing.

[ashwinisukale]

Code changes look perfect, can we format it like this,

  if options[:resource_type_id].present?
    resource_type_ids = options[:resource_type_id]
                          .split(",")
                          .map { |id| id.strip.underscore.dasherize }
   filter << { terms: { resource_type_id: resource_type_ids } }
  end

[digitaldogsbody]

I've done this, thanks for the suggestion :)

[ashwinisukale]

Looks great, thanks for addressing the changes :)