Partial matching of strings in generateScientificExpression

[linupi]

Description

This PR adds an additional CONTAINS_STRING condition to the generateScientificExpression function to filter within strings in scientific metadata.

Motivation

When defining our meta data schemas we realized that it would be very helpful for us to also filter on partially matching strings in the scientific metadata. However, so far there is only EQUAL_TO_STRING for text based entries in scientific metadata so we propose an additional CONTAINS_STRING which should work on simple strings as well as on lists. Here is an example:

"scientificMetadata": {
        "localContact": "John Doe",
        "experimentalists": [
                "John Doe",
                "Max Mustermann"
         ]

The idea of the proposed CONTAINS_STRING is that it would match e.g. John in both cases (as localContact as well as in experimentalists)

Changes:

• additinal condition for generateScientificExpression in mongo-queryable.js
• the related frontend changes can be found in https://github.com/SciCatProject/frontend/pull/974

Tests included/Docs Updated?

• [ ] Included for each change/fix?
• [ ] Passing? (Merge will not be approved unless this is checked)
• [ ] Docs updated?
• [ ] New packages used/requires npm install?
• [ ] Toggle added for new features?