Update to v2 version of vdl context.

[wes-smith]

adds types:

• OpticalBarcodeCredential
• TerseBitstringStatusListEntry
• AamvaDriversLicenseScannableInformation adds properties:
• terseStatusListIndex
• terseStatusListBaseUrl
• protectedComponentIndex

These additions are to support the Verifiable Credential Barcodes work.

• TerseBitstringStatusListEntry, terseStatusListIndex, and terseStatusListBaseUrl provide a space-efficient mechanism to use Bitstring Status List for status on driver's licenses.
• OpticalBarcodeCredential is a credential type used for securing data in an optical barcode, such as the PDF417 in a driver's license.
• AamvaDriversLicenseScannableInformation and protectedComponentIndex support securing AAMVA compliant PDF417s.

[wes-smith]

@awoie I've updated the PR description to give more insight into why these changes are valuable. Let me know if that is sufficient - if not, I will close the PR, raise an issue, then open a PR to address the issue.

[wes-smith]

@awoie On second thought, I am closing this PR to properly sequence multiple updates that are needed to the vdl context.

[awoie]

@awoie On second thought, I am closing this PR to properly sequence multiple updates that are needed to the vdl context.

sounds good, happy to review.