feat: Add Jenkins Lookup3 hash function

[cptr0]

Description of Change

I implemented the Jenkins Lookup3 hash function in C.
This includes the hashing function, an example usage, and a test. The implementation follows the algorithm described on the Wikipedia page (linked below).
https://en.wikipedia.org/wiki/Jenkins_hash_function

References

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes: