Adding Fuzz targets for lr planar

[Krishn1412]

Added a fuzz target to check the robustness of lr planar function.

[coveralls]

Pull Request Test Coverage Report for Build 15042146200

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 95.236%

---

Totals
Change from base Build 14945626099:	0.0%
Covered Lines:	18733
Relevant Lines:	19670

---

💛 - Coveralls

[Krishn1412]

Hey @IvanIsCoding, could you take a look at this PR? TIA.

[IvanIsCoding]

@Krishn1412 I will take a look, but it seems that right now we are not asserting much about the function?

I need to check our source code if there are ways to panic. If there aren’t, I’m not sure how this fuzz will benefit us.

[IvanIsCoding]

I'll stand corrected, there are places our code could, in theory, panic:

rustworkx/rustworkx-core/src/planar/lr_planar.rs

Line 393 in 30897c5

unreachable!()

I think we might be able to make it stronger but as is I think this should be fine.

A possible follow up is trying to generate random planar graphs and augmenting them to be non-planar.