[PRETEST]: Add a research doc for relevant testing frameworks

[Siddhi-agg]

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

• N
• Y
  ref [LFX] A Test Framework: KCL needed a new testing framework for unit testing and e2e testing #593

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

research/Cargo_test.md

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

This PR is the pretest for the LFX Mentorship project from the above referenced issue. This is still a work in progress. I have added my research for cargo test framework in Rust programming language and will be adding a similar research document for other relevant testing frameworks as well.

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 13258775335

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 42.022%

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Totals
Change from base Build 13257127662:	0.0%
Covered Lines:	4174
Relevant Lines:	9933

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💛 - Coveralls