Add accout.signRaw function to sign a message without prefix

[blackmoshui]

Description

Fix #6955

Please include a summary of the changes and be sure to follow our Contribution Guidelines.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run lint with success and extended the tests and types if necessary.
• I ran npm run test:unit with success.
• I ran npm run test:coverage and my test cases cover all the lines and branches of the added code.
• I ran npm run build and tested dist/web3.min.js in a browser.
• I have tested my code on the live network.
• I have checked the Deploy Preview and it looks correct.
• I have updated the CHANGELOG.md file in the root folder.
• I have linked Issue(s) with this PR in "Linked Issues" menu.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.51%. Comparing base (d3baae6) to head (2a5d298).

Additional details and impacted files

@@           Coverage Diff           @@
##              4.x    #7346   +/-   ##
=======================================
  Coverage   94.50%   94.51%           
=======================================
  Files         217      217           
  Lines        8487     8491    +4     
  Branches     2343     2345    +2     
=======================================
+ Hits         8021     8025    +4     
  Misses        466      466           

Flag	Coverage Δ
UnitTests	94.51% <100.00%> (+<0.01%)	⬆️

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[jdevcs]

also need update of https://github.com/blackmoshui/web3.js/blob/fix-6955-add-raw-sign-function/packages/web3-eth-accounts/CHANGELOG.md

[jdevcs]

@blackmoshui thanks

[blackmoshui]

also need update of https://github.com/blackmoshui/web3.js/blob/fix-6955-add-raw-sign-function/packages/web3-eth-accounts/CHANGELOG.md

Added. 😄 Thanks for the reminder.

[jdevcs]

@blackmoshui before merging this PR, there are merge conflicts needs to be fixed, thanks

[blackmoshui]

@blackmoshui before merging this PR, there are merge conflicts needs to be fixed, thanks

Updated.