feat: Add encode / decode messages to support

[beguene]

This adds an encodeMessage, decodeMessage and hashMessage functions to support arbitrary message signing
more details in #1231

cc: @janniks

Checklist

• Code is commented where needed
• Unit test coverage for new or modified code paths
• npm run test passes
• Changelog is updated
• Tag 1 of @yknl or @zone117x for review

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[codecov-commenter]

Codecov Report

Merging #1232 (a073768) into master (ade4444) will increase coverage by 0.05%.
The diff coverage is 100.00%.

❗ Current head a073768 differs from pull request most recent head cd444f9. Consider uploading reports for the commit cd444f9 to get more accurate results

@@            Coverage Diff             @@
##           master    #1232      +/-   ##
==========================================
+ Coverage   64.00%   64.06%   +0.05%     
==========================================
  Files         123      124       +1     
  Lines        8574     8588      +14     
  Branches     1818     1818              
==========================================
+ Hits         5488     5502      +14     
  Misses       2978     2978              
  Partials      108      108              

Impacted Files	Coverage Δ
packages/encryption/src/messageSignature.ts	100.00% <100.00%> (ø)

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