refactor and cleanup the compile command

[SparkYuan]

What type of PR is this?

/kind refactor
/kind cleanup

What this PR does / why we need it:

refactor and cleanup the compile command to make it more general and readable

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 4172517639

• 11 of 29 (37.93%) changed or added relevant lines in 2 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.05%) to 72.116%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/generator/kcl/kcl_generator.go	11	13	84.62%
pkg/cmd/compile/options.go	0	16	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/cmd/compile/options.go	1	34.62%
pkg/engine/operation/watch.go	1	88.28%

Totals
Change from base Build 4171617236:	0.05%
Covered Lines:	4676
Relevant Lines:	6484

---

💛 - Coveralls