feat: inlayhint for config key type

[He1pa]

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

• [ ] N
• [x] Y enhance for https://github.com/orgs/kcl-lang/discussions/1657

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):

• [x] N
• [ ] Y

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

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

[Peefy]

I think the discussion is about an auto-completion feature rather than a type hint feature. 🤔

[coveralls]

Pull Request Test Coverage Report for Build 10990778156

Details

• 43 of 47 (91.49%) changed or added relevant lines in 2 files are covered.
• 13 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.002%) to 70.591%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
kclvm/sema/src/ty/mod.rs	14	15	93.33%
kclvm/sema/src/advanced_resolver/node.rs	29	32	90.63%
<!--	Total:	43	47	91.49%	-->

Files with Coverage Reduction	New Missed Lines	%
kclvm/tools/src/LSP/src/tests.rs	1	98.61%
kclvm/tools/src/LSP/src/state.rs	12	82.73%
<!--	Total:	13		-->

Totals
Change from base Build 10917873891:	-0.002%
Covered Lines:	51306
Relevant Lines:	72681

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💛 - Coveralls