Fixes for #11716

[qqmyers]

What this PR does / why we need it: The original PR did not use a valid method for determining whether the store supports directUpload. This PR addresses that, along with making several other minor improvements:

• using a more direct method to get the directDownload flag to avoid sending the dataset as a parameter and instantiating a StorageIO object
• moves the changelog entry to 6.9 as the original feature to extend the get storage driver API #11716 did not make 6.8
• clarifies some documentation
• adds an uploadOutOfBand boolean entry (stores with this = true allow creating file entries by just sending metadata and a storageIdentifier - like S3 direct upload except that the files have to have been put in place by some out-of-band mechanism (e.g. manual copying into a file store)
• adds a unit test to assure that the store properties are read correctly (when stored as System properties)

Which issue(s) this PR closes:

• Closes #

Special notes for your reviewer:

Suggestions on how to test this: Call these apis for datasets/dataverses and verify that the correct store is returned and that the values match what is set (e.g. as jvm-options).

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?:

Additional documentation:

[coveralls]

coverage: 23.788% (+0.01%) from 23.778%
when pulling e8e5875 on GlobalDataverseCommunityConsortium:Fix-dataset-storageDriver_api
into 53bff4c on IQSS:develop.

[landreev]

@qqmyers Could you please resolve the conflicts and sync up the branch. (the conflicts are in the changelog and trivial)