Add ls subcommand

[nao1215]

No description provided.

[github-actions]

🚫 [golangci] _{reported by reviewdog 🐶}
ST1000: at least one file in a package should have a package comment (stylecheck)

[github-actions]

HOTTEST report

PASS	FAIL	SKIP	TOTAL	DURATION
67	0	3	70	1.698947893s

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Reported by hottest

[github-actions]

Code Metrics Report

	main (df25e67)	#9 (5e2c602)	+/-
Coverage	23.6%	19.6%	-4.0%
Test Execution Time	30s	4s	-26s

Details

  |                     | main (df25e67) | #9 (5e2c602) |  +/-  |
  |---------------------|----------------|--------------|-------|
- | Coverage            |          23.6% |        19.6% | -4.0% |
  |   Files             |             17 |           19 |    +2 |
  |   Lines             |            347 |          403 |   +56 |
- |   Covered           |             82 |           79 |    -3 |
+ | Test Execution Time |            30s |           4s |  -26s |

Code coverage of files in pull request scope (36.9% → 24.2%)

Files	Coverage	+/-
app/di/wire_gen.go	0.0%	0.0%
app/domain/model/s3.go	93.6%	-4.2%
app/external/s3.go	0.0%	0.0%
app/interactor/s3.go	0.0%	0.0%
cmd/subcmd/common.go	0.0%	0.0%
cmd/subcmd/s3hub/common.go	4.2%	+4.2%
cmd/subcmd/s3hub/ls.go	0.0%	-100.0%
cmd/subcmd/s3hub/mb.go	0.0%	0.0%
cmd/subcmd/s3hub/root.go	0.0%	-6.7%

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Reported by octocov