fix: prevent simple inclusion of a valid mnemonic

[arirubinstein]

Description

Ref: #9122

This PR adds a validation check to prevent simple inclusion of a valid mnemonic in a tx by adding a validation to the tx factory.

Author Checklist

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I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
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• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
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I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[julienrbrt]

utACK, I didn't know it was a thing 😂

[codecov]

Codecov Report

Merging #13670 (a5fe7df) into main (6b4db20) will increase coverage by 0.12%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13670      +/-   ##
==========================================
+ Coverage   54.80%   54.92%   +0.12%     
==========================================
  Files         647      656       +9     
  Lines       55794    56202     +408     
==========================================
+ Hits        30579    30871     +292     
- Misses      22724    22807      +83     
- Partials     2491     2524      +33     

Impacted Files	Coverage Δ
client/tx/factory.go	29.21% <100.00%> (+0.80%)	⬆️
x/group/keeper/keeper.go	56.25% <0.00%> (-0.40%)	⬇️
tx/textual/valuerenderer/timestamp.go	89.28% <0.00%> (ø)
tx/textual/valuerenderer/bytes.go	62.50% <0.00%> (ø)
tx/textual/valuerenderer/valuerenderer.go	72.41% <0.00%> (ø)
tx/textual/valuerenderer/string.go	66.66% <0.00%> (ø)
tx/textual/valuerenderer/coins.go	73.17% <0.00%> (ø)
tx/textual/valuerenderer/duration.go	78.22% <0.00%> (ø)
tx/textual/valuerenderer/message.go	64.22% <0.00%> (ø)
tx/textual/valuerenderer/dec.go	50.00% <0.00%> (ø)
... and 1 more

[tac0turtle]

This is awesome thank you!!

[alexanderbez]

Didn't even think of this! Neat :)