feat: add net.CIDR_subnets 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 multiple networks 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 14484569177

Details

• 220 of 296 (74.32%) changed or added relevant lines in 2 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.06%) to 70.537%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
kclvm/runtime/src/net/mod.rs	219	295	74.24%

Files with Coverage Reduction	New Missed Lines	%
kclvm/runtime/src/net/mod.rs	1	58.48%
kclvm/sema/src/advanced_resolver/node.rs	1	84.97%

Totals
Change from base Build 14460419160:	0.06%
Covered Lines:	53521
Relevant Lines:	75877

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💛 - Coveralls