[Feature] Add Excel Loader to load .xlsx

[eren-darici]

Description

• Excel Loader created
• Dependencies added
• Basic tests are created

How Has This Been Tested?

• Created test_excel.py which includes multi-sheet validation.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes most issues related Excel
• Made sure Checks passed

[deshraj]

Overall looks great. Left a minor comment.

Thanks for the contrbution. ❤️ 🚀

[deven298]

Left few comments. Thanks for adding this btw! ❤️

[deven298]

LGTM!

@eren-darici Could you please resolve the conflicts? Also, it would be great it you can add docs for this here.
I will merge this and release it in next package release.