TA-3148: Update NodeExportTransport and export/import logic to work with JSON files

[Buqeta]

Description

This PR updates the NodeExportTransport's configuration property to object instead of string. Along with this, the batch import/export logic was updated to work with JSON files. The same is true for diffing.

Other:

• Created a replacer function which tells the JSON.stringify function how to stringify a Map, because it doesn't support Maps. This was causing problems when trying to stringify ManifestTransport's dependenciesByVersion property, because it's a Map.
• Updated the tests to work with the new changes.

Checklist

• I have self-reviewed this PR
• I have tested the change and proved that it works in different scenarios
• I have updated docs if needed