fix(utils): synchronous version of sha256 digest

[simonas-notcat]

What issue is this PR fixing

Native browser crypto API is async We need a sync version of sha256 for the computeEntryHash method.

https://stackoverflow.com/a/73600052

Quality

Check all that apply:

• [X] I want these changes to be integrated
• [X] I successfully ran pnpm i, pnpm build, pnpm test, pnpm test:browser locally.
• [X] I allow my PR to be updated by the reviewers (to speed up the review process).
• [ ] I added unit tests.
• [X] I added integration tests.
• [ ] I did not add automated tests because _____, and I am aware that a PR without tests will likely get rejected.

Details

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[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01% :warning:

Comparison is base (e2e794f) 84.93% compared to head (5396c5e) 84.93%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## next #1253 +/- ## ========================================== - Coverage 84.93% 84.93% -0.01% ========================================== Files 167 167 Lines 18132 18131 -1 Branches 2036 2036 ========================================== - Hits 15400 15399 -1 Misses 2732 2732 ``` | [Files Changed](https://app.codecov.io/gh/uport-project/veramo/pull/1253?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=uport-project) | Coverage Δ | | |---|---|---| | [packages/utils/src/credential-utils.ts](https://app.codecov.io/gh/uport-project/veramo/pull/1253?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=uport-project#diff-cGFja2FnZXMvdXRpbHMvc3JjL2NyZWRlbnRpYWwtdXRpbHMudHM=) | `100.00% <100.00%> (ø)` | |

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