Add credentials V2 context to loaded contexts.

[aljones15]

Awaits:

• [ ] A full release of the VC 2.0 context library.
• [ ] Address #9

[codecov-commenter]

Codecov Report

Merging #6 (8bf2303) into main (aacf8cf) will not change coverage. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #6 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 1 1 Lines 18 22 +4 ========================================= + Hits 18 22 +4 ``` | [Files](https://app.codecov.io/gh/digitalbazaar/bedrock-credentials-context/pull/6?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar) | Coverage Δ | | |---|---|---| | [lib/index.js](https://app.codecov.io/gh/digitalbazaar/bedrock-credentials-context/pull/6?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar#diff-bGliL2luZGV4Lmpz) | `100.00% <100.00%> (ø)` | | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/digitalbazaar/bedrock-credentials-context/pull/6?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/digitalbazaar/bedrock-credentials-context/pull/6?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). Last update [aacf8cf...8bf2303](https://app.codecov.io/gh/digitalbazaar/bedrock-credentials-context/pull/6?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar).

[davidlehn]

This is done in 5.0.0. It was a bit easier to use another similar PR and leave this alone. Branch will be removed when other references are cleaned up.