Expose functions for merging schemas from JSON schema samples plugins

[glowcloud]

We can expose the functions existing in JSON Schema 5 samples

swagger-ui/src/core/plugins/json-schema-5-samples/fn/index.js

Line 59 in c0e3eb6

const liftSampleHelper = (oldSchema, target, config = {}) => {

and JSON Schema 2020-12 samples

swagger-ui/src/core/plugins/json-schema-2020-12-samples/fn/core/merge.js

Line 7 in c0e3eb6

const merge = (target, source, config = {}) => {

so that we can use them interchangeably for merging schemas outside of the function for getting examples (sampleForSchemaGeneric in both plugins).

This will help with the cases described in #9763.

[glowcloud]

Addressed by #9766