why there is a breaking change by updating the library with new identity-mdoc, storage related and key creation changes?

[vaimut]

With reference to the commit #467 and other changes why the storage got restructured like changing the file names from IC_AndroidKeystore_ to IC_Document_<> and also credential class is being converted to document

So our question is
1)Whether migration from credentials to document is planned?
2)Previously we used credential key and now there is no option to do it. so is there any migration planned for keys as well because now we can see only pending credential to create keys in the key-store
3)Whether this will be the finalised changes at the storage level and key creation level?
4)Is there is any road map or milestone for the stable library version ?