Convert x/bank query CLI commands to use gRPC query client

[aaronc]

ref: #5921

This PR:

• converts the x/bank balances and total CLI query commands to use the gRPC QueryClient
• updates client.Context.PrintOutput to properly work with protobuf and amino (including unit tests), and removes client.Context.Println which was initially intended to replace PrintOutput for protobuf but is no longer needed

---

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

[codecov]

Codecov Report

Merging #6367 into master will increase coverage by 0.07%.
The diff coverage is 48.27%.

@@            Coverage Diff             @@
##           master    #6367      +/-   ##
==========================================
+ Coverage   55.98%   56.06%   +0.07%     
==========================================
  Files         466      466              
  Lines       27908    27904       -4     
==========================================
+ Hits        15623    15643      +20     
+ Misses      11180    11149      -31     
- Partials     1105     1112       +7     

[lgtm-com]

This pull request introduces 2 alerts when merging 9d34409 into 65ea305 - view on LGTM.com

new alerts:

• 2 for Useless assignment to local variable

[fedekunze]

ACK ☕