feat: add api for get kcl package info.

[zong-zhe]

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

• N
• Y

fix #155

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

pkg/api/kpm_pkg.go

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

add api for kcl package info.

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

[coveralls]

Pull Request Test Coverage Report for Build 5898303521

• 27 of 44 (61.36%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.3%) to 42.255%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/package/package.go	0	6	0.0%
pkg/api/kpm_pkg.go	24	35	68.57%

Totals
Change from base Build 5889056605:	0.3%
Covered Lines:	1102
Relevant Lines:	2608

---

💛 - Coveralls

[Peefy]

LGTM