Add flag to support migrate multi applications config at once

[khanhtc1202]

What this PR does:

Add --dirs flag to pipectl migrate application config command.

Why we need it:

We want to make the pipectl migrate application config command work with multiple applications at once

Which issue(s) this PR fixes:

Part of #5542
Follow #6175

Does this PR introduce a user-facing change?:

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[Warashi]

👍🏻

[codecov]

Codecov Report

❌ Patch coverage is 0% with 33 lines in your changes missing coverage. Please review.
✅ Project coverage is 28.42%. Comparing base (8b0b05c) to head (c90743e).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/app/pipectl/cmd/migrate/application_config.go	0.00%	33 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6181      +/-   ##
==========================================
- Coverage   28.44%   28.42%   -0.03%     
==========================================
  Files         537      537              
  Lines       57534    57566      +32     
==========================================
- Hits        16367    16361       -6     
- Misses      39895    39933      +38     
  Partials     1272     1272              

Flag	Coverage Δ
.	23.00% <0.00%> (-0.03%)	⬇️
.-pkg-app-pipedv1-plugin-analysis	62.85% <ø> (ø)
.-pkg-app-pipedv1-plugin-kubernetes	60.24% <ø> (ø)
.-pkg-app-pipedv1-plugin-kubernetes_multicluster	67.48% <ø> (ø)
.-pkg-app-pipedv1-plugin-scriptrun	54.83% <ø> (ø)
.-pkg-app-pipedv1-plugin-terraform	38.31% <ø> (ø)
.-pkg-app-pipedv1-plugin-wait	35.51% <ø> (ø)
.-pkg-app-pipedv1-plugin-waitapproval	68.62% <ø> (ø)
.-pkg-plugin-sdk	50.37% <ø> (ø)
.-tool-actions-gh-release	19.23% <ø> (ø)
.-tool-actions-plan-preview	25.30% <ø> (ø)
.-tool-codegen-protoc-gen-auth	0.00% <ø> (ø)

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[ffjlabo]

LGTM