Feat(kcl-vet): add ast builder for kcl-vet.

[zong-zhe]

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

• N
• Y

issue #67

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

KCL-Vet

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 ast expr builder for kcl-vet from json/yaml Value.

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

6. Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[coveralls]

Pull Request Test Coverage Report for Build 3209076493

• 399 of 417 (95.68%) changed or added relevant lines in 4 files are covered.
• 304 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+1.6%) to 61.395%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
kclvm/tools/src/vet/expr_builder.rs	187	196	95.41%
kclvm/tools/src/vet/tests.rs	207	216	95.83%

Files with Coverage Reduction	New Missed Lines	%
kclvm/compiler/src/codegen/llvm/context.rs	3	74.15%
kclvm/compiler/src/codegen/llvm/utils.rs	6	86.96%
kclvm/3rdparty/rustc_span/src/analyze_source_file.rs	10	75.26%
kclvm/parser/src/parser/expr.rs	285	81.58%

Totals
Change from base Build 3132651737:	1.6%
Covered Lines:	24229
Relevant Lines:	39464

---

💛 - Coveralls

[ldxdl]

UT coverage of the major file kclvm/tools/src/vet/expr_builder.rs is pretty low...
More unit tests are required to ensure UT coverage to be at least 95%.

[ldxdl]

LGTM

[Peefy]

LGTM