enhance: enhance fmt tool.

[He1pa]

1.save empty line between comments,
2. fix logicc of empty line between stmt

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

• N
• Y fix Disable auto-removal of empty line #1840

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

fmt

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

[coveralls]

Pull Request Test Coverage Report for Build 13177385716

Details

• 12 of 12 (100.0%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.002%) to 70.347%

---

Files with Coverage Reduction	New Missed Lines	%
kclvm/sema/src/advanced_resolver/node.rs	1	84.97%

Totals
Change from base Build 13174900010:	0.002%
Covered Lines:	52563
Relevant Lines:	74720

---

💛 - Coveralls

[legal90]

Thank you very much for the fix, @He1pa !