Add tests for Project euler problem 14 solution (#1713)

* 📦 NEW: Added solution for ProjectEuler-007

* 🐛 FIX: Spelling mistake fixes

* 👌 IMPROVE: changed variable name from `inc` to `candidateValue` and thrown error in case of invalid input

* 👌 IMPROVE: Modified the code

* 👌 IMPROVE: Added test case for ProjectEuler Problem001

* 👌 IMPROVE: Added test cases for Project Euler Problem 4

* 👌 IMPROVE: auto prettier fixes

* 📦 NEW: Testcases for Project Euler Problem 14

* Updated Documentation in README.md

* 👌 IMPROVE: code improvements

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Co-authored-by: Omkarnath Parida <omkarnath.parida@yocket.in>
Co-authored-by: pomkarnath98 <pomkarnath98@users.noreply.github.com>