feat: add net.CIDR_subnet function

[johngmyers]

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

• N
• Y

re #1857

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

kclvm/runtine/src/net

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

Adds a function to allocate a network out of a CIDR.

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 14416694431

Details

• 147 of 217 (67.74%) changed or added relevant lines in 2 files are covered.
• 13 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.02%) to 70.462%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
kclvm/runtime/src/net/mod.rs	146	216	67.59%

Files with Coverage Reduction	New Missed Lines	%
kclvm/sema/src/advanced_resolver/node.rs	1	84.97%
kclvm/tools/src/LSP/src/state.rs	12	72.41%

Totals
Change from base Build 14338841824:	-0.02%
Covered Lines:	53263
Relevant Lines:	75591

---

💛 - Coveralls

[He1pa]

lgtm. by the way, Are there more PRs about this issue? We plan to release a new version this week. @johngmyers

[johngmyers]

I am working through the four functions and will delete the two existing ones, but won't be done this week.