[#491] Default app config across app types

[GrootZ7]

Description

This PR implements the default app config across app types feature that allows a default app config to be created for the whole application, and allows specific fields to be overridden for each platform. If a version is not specified in these platform-specific config file names, these patches should be automatically applied to all config versions unless a platform-specific patch for that version is also defined.

Resolves #491

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Checklist:

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