Refactor binary to hexadecimal conversion program

[prem-2006]

Updated the binary to hexadecimal conversion program to read binary as a string for safer input handling and added validation for binary digits.

Description of Change

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
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Notes: