use pure js hash function for marked code block generation

[habdelra]

This fixes a bug where the md5 hash function was not running in the Fastboot env of the worker during indexing. we have replaced this with a pure js hash function.

This solves the indexing error:

[worker 109608 priority 0]: Promise rejected TypeError: Cannot read properties of undefined (reading 'encode')
Please report this to https://github.com/markedjs/marked.
    at getUInt8Buffer (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:412524:24)
    at calculate (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:412562:18)
    at md5 (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:412585:10)
    at _Renderer.code (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.2a0fc7d9e4a377bfdb0a.js:19687:95)
    at renderer.<computed> [as code] (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:595221:36)
    at _Parser.parse (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:594850:34)
    at parse (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:594804:19)
    at Marked.parse (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:595367:20)
    at Function.marked [as parse] (/tmp/tmp-109608-FsRSCx8brLfb/assets/chunk.ba6f521a38934cbdb921.js:595396:25)
    at markedSync

h/t @IanCal 🙏

[github-actions]

Host Test Results

    1 files  ±0      1 suites  ±0   23m 22s ⏱️ -22s
773 tests ±0  771 ✔️ ±0  2 💤 ±0  0 ❌ ±0 
778 runs  ±0  776 ✔️ ±0  2 💤 ±0  0 ❌ ±0 

Results for commit a105d35. ± Comparison against base commit 05d4cb6.

[IanCal]

Lgtm. Not executed but this is a pretty well used hash function, not cryptographically safe but that's not needed here.