feat(app)!: use built-in cobra completion

[aaronc]

Description

This will provide a better dev UX, see also: cosmos/cosmos-sdk#13548. Cobra has its own completion command which is better than this old tmcli command.

Also, let's do this: https://carlosbecker.com/posts/golang-completions-cobra/

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Author Checklist

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please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• 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
• reviewed "Files changed" and left comments if necessary
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Reviewers Checklist

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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)

[ryanchristo]

Pre-approving. Can you add a changelog entry? 🙏

[codecov]

Codecov Report

Merging #1546 (6b97cd1) into main (ac275f1) will decrease coverage by 0.25%.
The diff coverage is n/a.

❗ Current head 6b97cd1 differs from pull request most recent head 99e3943. Consider uploading reports for the commit 99e3943 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1546      +/-   ##
==========================================
- Coverage   78.69%   78.43%   -0.26%     
==========================================
  Files         251      251              
  Lines       18851    18855       +4     
==========================================
- Hits        14834    14789      -45     
- Misses       3153     3201      +48     
- Partials      864      865       +1     

Impacted Files	Coverage Δ
app/client/cli/root.go	61.26% <ø> (-0.18%)	⬇️
...edit/base/types/v1/msg_add_allowed_bridge_chain.go	0.00% <0.00%> (-66.67%)	⬇️
...t/base/types/v1/msg_set_class_creator_allowlist.go	41.66% <0.00%> (-16.67%)	⬇️
...cocredit/base/types/v1/msg_remove_class_creator.go	46.15% <0.00%> (-15.39%)	⬇️
x/ecocredit/base/types/v1/msg_seal_batch.go	53.33% <0.00%> (-13.34%)	⬇️
x/ecocredit/base/types/v1/msg_add_class_creator.go	53.33% <0.00%> (-13.34%)	⬇️
...t/base/types/v1/msg_remove_allowed_bridge_chain.go	53.33% <0.00%> (-13.34%)	⬇️
x/data/msg_anchor.go	80.00% <0.00%> (-13.34%)	⬇️
x/data/msg_define_resolver.go	80.00% <0.00%> (-13.34%)	⬇️
x/ecocredit/base/types/v1/msg_update_class_fee.go	56.25% <0.00%> (-12.50%)	⬇️
... and 19 more