Problem: swagger doc is not embed in api service

[yihuang]

Closes: #108

Soluton:

• register swagger service in app
• add swagger gen scripts

👮🏻👮🏻👮🏻 !!!! REFERENCE THE PROBLEM YOUR ARE SOLVING IN THE PR TITLE AND DESCRIBE YOUR SOLUTION HERE !!!! DO NOT FORGET !!!! 👮🏻👮🏻👮🏻

PR Checklist:

• Have you read the CONTRIBUTING.md?
• Does your PR follow the C4 patch requirements?
• Have you rebased your work on top of the latest master?
• Have you checked your code compiles? (make)
• Have you included tests for any non-trivial functionality?
• Have you checked your code passes the unit tests? (make test)
• Have you checked your code formatting is correct? (go fmt)
• Have you checked your basic code style is fine? (golangci-lint run)
• If you added any dependencies, have you checked they do not contain any known vulnerabilities? (go list -json -m all | nancy sleuth)
• If your changes affect the client infrastructure, have you run the integration test?
• If your changes affect public APIs, does your PR follow the C4 evolution of public contracts?
• If your code changes public APIs, have you incremented the crate version numbers and documented your changes in the CHANGELOG.md?
• If you are contributing for the first time, please read the agreement in CONTRIBUTING.md now and add a comment to this pull request stating that your PR is in accordance with the Developer's Certificate of Origin.

Thank you for your code, it's appreciated! :)

[codecov]

Codecov Report

Merging #110 (80d82ad) into main (3ea70c5) will increase coverage by 4.24%.
The diff coverage is 36.63%.

@@            Coverage Diff             @@
##             main     #110      +/-   ##
==========================================
+ Coverage   21.51%   25.76%   +4.24%     
==========================================
  Files          27       34       +7     
  Lines        1729     2267     +538     
==========================================
+ Hits          372      584     +212     
- Misses       1324     1643     +319     
- Partials       33       40       +7     

Impacted Files	Coverage Δ
app/prefix.go	0.00% <0.00%> (ø)
x/cronos/keeper/grpc_query.go	0.00% <0.00%> (ø)
x/cronos/keeper/hooks.go	0.00% <0.00%> (ø)
x/cronos/keeper/msg_server.go	6.45% <0.00%> (ø)
x/cronos/module.go	59.64% <0.00%> (-2.17%)	⬇️
x/cronos/types/codec.go	0.00% <0.00%> (ø)
x/cronos/types/query.pb.gw.go	0.00% <0.00%> (ø)
x/cronos/types/tracer.go	0.00% <0.00%> (ø)
app/app.go	4.03% <2.17%> (+0.08%)	⬆️
x/cronos/proposal_handler.go	6.66% <6.66%> (ø)
... and 17 more

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[thomas-nguy]

lgtm