refactor: app configuration model definition

[SparkYuan]

What type of PR is this?

/kind refactor

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Additional documentation e.g., design docs, usage docs, etc.:

[coveralls]

Pull Request Test Coverage Report for Build 7970150687

Details

• -27 of 257 (89.49%) changed or added relevant lines in 2 files are covered.
• 10 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.2%) to 76.833%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/apis/core/v1/workload/workload.go	74	78	94.87%
pkg/apis/core/v1/workload/container/container.go	156	179	87.15%

Files with Coverage Reduction	New Missed Lines	%
pkg/engine/operation/parser/parser.go	3	79.27%
pkg/cmd/destroy/options.go	7	81.86%

Totals
Change from base Build 7968280233:	0.2%
Covered Lines:	9021
Relevant Lines:	11741

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💛 - Coveralls