Change DeployTargets to DeployTargetsByPlugin in model.Application

[khanhtc1202]

What this PR does:

as title

Why we need it:

We need to use not just deploy targets but plugins while deploying applications and the current model.Application that contains only deployTargets is not enough. By adding this, pipedv1 can use both plugins and deploy targets while performing the deployment task.

Which issue(s) this PR fixes:

Part of #4980 #5252

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):

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 36 lines in your changes missing coverage. Please review.

Project coverage is 26.43%. Comparing base (db1d74e) to head (42ef6d8).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/app/pipectl/cmd/migrate/database.go	0.00%	20 Missing ⚠️
pkg/model/application.go	0.00%	7 Missing ⚠️
pkg/datastore/datastoretest/datastore.mock.go	0.00%	4 Missing ⚠️
pkg/datastore/applicationstore.go	0.00%	2 Missing ⚠️
pkg/app/piped/trigger/deployment.go	0.00%	1 Missing ⚠️
pkg/app/pipedv1/trigger/deployment.go	0.00%	1 Missing ⚠️
pkg/app/server/grpcapi/api.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5543      +/-   ##
==========================================
- Coverage   26.43%   26.43%   -0.01%     
==========================================
  Files         465      465              
  Lines       49860    49885      +25     
==========================================
+ Hits        13182    13188       +6     
- Misses      35624    35643      +19     
  Partials     1054     1054              

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