PoA Improvements #2

[Phanco]

What was the problem?

This PR resolves #8964

How was it solved?

1. RegisterAuthorityParams reordered
2. Skipped as it has been resolved by PR Update poa module schema validation and endpoint #8967
3. isBufferArrayOrdered in initGenesisState
4. shuffleValidatorList in PoA is removed and solely using PoS

How was it tested?

Test Cases Passed

[codecov]

Codecov Report

Merging #8991 (3db42a3) into release/6.1.0 (3db42a3) will not change coverage.
The diff coverage is n/a.

❗ Current head 3db42a3 differs from pull request most recent head f10ff86. Consider uploading reports for the commit f10ff86 to get more accurate results

@@              Coverage Diff               @@
##           release/6.1.0    #8991   +/-   ##
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  Coverage          84.36%   84.36%           
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  Files                650      650           
  Lines              24026    24026           
  Branches            3494     3494           
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  Hits               20269    20269           
  Misses              3757     3757