Remove duplicate tx commands for auth

[sahith-narahari]

Description

This removes auth tx sub commands from simd tx

closes: #XXXX

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Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #7788 into master will increase coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #7788      +/-   ##
==========================================
+ Coverage   54.19%   54.20%   +0.01%     
==========================================
  Files         610      609       -1     
  Lines       38872    38859      -13     
==========================================
  Hits        21065    21065              
+ Misses      15650    15637      -13     
  Partials     2157     2157              

[amaury1093]

Code lgtm 👍 Would like to see a changelog entry

[alessio]

utACK'd - pending @amaurymartiny's comments