Hacktoberfest: Added Octal Number to Hexadecimal Number Conversion Algorithm (#10533)

* Added Octal to Hexadecimal Conversion program under 'conversions' directory

* Update conversions/octal_to_hexadecimal.py

fix: minor improvement to directly return hexadecimal value

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* Update conversions/octal_to_hexadecimal.py

fix: improvement updates to octal to hexadecimal

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* Update conversions/octal_to_hexadecimal.py

fix: Readablility improvements to octal to hexadecimal convertor

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* Update conversions/octal_to_hexadecimal.py

fix: readability improvements in octal_to_hexadecimal.py

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* Update conversions/octal_to_hexadecimal.py

fix: readability improvements in octal_to_hexadecimal.py

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* fix: Fixed all the errors in octal_to_hexadecimal.py after commiting suggested changes

* fix: modified the prefix of hex numbers to the '0x' standard in octal_to_hexadecimal.py

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Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>