Problem: unsuppored sign mode SIGN_MODE_TEXTUAL in bank transfer

[mmsqe]

Closes: #XXX

Description

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For contributor use:

• 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

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For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 46.56%. Comparing base (5acb559) to head (970285e).
Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
app/app.go	83.33%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #537      +/-   ##
===========================================
+ Coverage    46.45%   46.56%   +0.10%     
===========================================
  Files          181      181              
  Lines        14477    14506      +29     
===========================================
+ Hits          6725     6754      +29     
+ Misses        7045     7037       -8     
- Partials       707      715       +8     

Files with missing lines	Coverage Δ
app/app.go	76.38% <83.33%> (+0.14%)	⬆️

... and 2 files with indirect coverage changes