feat: make 'run' command supports ModSpec

[zong-zhe]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

re #289

2. What is the scope of this PR (e.g. component or file name):

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

[Peefy]

LGTM

[coveralls]

Pull Request Test Coverage Report for Build 11588807693

Details

• 2 of 47 (4.26%) changed or added relevant lines in 2 files are covered.
• 8 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.3%) to 41.759%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/visitor/visitor.go	2	9	22.22%
pkg/downloader/source.go	0	38	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/settings/settings.go	8	57.36%

Totals
Change from base Build 11573696389:	-0.3%
Covered Lines:	3666
Relevant Lines:	8779

---

💛 - Coveralls