fix: add error message in GetByteCode()

[da1suk8]

Description

I added error message in GetByteCode().

Motivation and context

An error occurred in GetByteCode, but the error is not returned.

How has this been tested?

Screenshots (if appropriate):

Checklist:

• I followed the contributing guidelines and code of conduct.
• I have added a relevant changelog to CHANGELOG.md
• I have added tests to cover my changes.
• I have updated the documentation accordingly.
• I have updated API documentation client/docs/swagger-ui/swagger.yaml

[codecov]

Codecov Report

Merging #742 (d3bc33e) into main (1e53873) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #742      +/-   ##
==========================================
- Coverage   62.05%   62.04%   -0.01%     
==========================================
  Files         877      877              
  Lines       98977    98977              
==========================================
- Hits        61416    61412       -4     
- Misses      33944    33949       +5     
+ Partials     3617     3616       -1     

Impacted Files	Coverage Δ
store/types/store.go	56.25% <ø> (ø)
x/wasm/keeper/keeper.go	86.16% <100.00%> (ø)
x/token/msgs.go	32.48% <0.00%> (-4.07%)	⬇️
x/token/validation.go	70.90% <0.00%> (-1.82%)	⬇️
crypto/keys/internal/ecdsa/privkey.go	82.45% <0.00%> (-1.76%)	⬇️
x/collection/msgs.go	39.44% <0.00%> (+1.11%)	⬆️

[zemyblue]

Please, add changelog.

[shiki-tak]

LGTM