feat: implement One-Time Pad cipher (#6941)

[duvvuvenkataramana]

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase.
• All functions and variable names follow Java naming conventions.
• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• All new code is formatted with clang-format -i --style=file path/to/your/file.java

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.61%. Comparing base (14c0b08) to head (d64be77).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7096      +/-   ##
============================================
+ Coverage     78.60%   78.61%   +0.01%     
- Complexity     6815     6823       +8     
============================================
  Files           764      765       +1     
  Lines         22580    22599      +19     
  Branches       4441     4443       +2     
============================================
+ Hits          17749    17767      +18     
  Misses         4117     4117              
- Partials        714      715       +1     

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[duvvuvenkataramana]

@DenizAltunkapan @yanglbme @alxkm
Hi maintainers 👋,

I have completed the implementation of the One-Time Pad Cipher along with unit tests, following all contribution guidelines:

Code formatted using clang-format

Added detailed Javadoc and reference to the algorithm concept

100% test coverage for new changes

All CI checks have passed successfully

Could you please review the PR and merge.
Thank you for your guidance and efforts in maintaining this repository 🙏

[duvvuvenkataramana]

Hi @DenizAltunkapan @yanglbme @alxkm 👋,

I’ve completed the One-Time Pad Cipher implementation and ensured everything follows the contribution guidelines:

✔ Code fully formatted

✔ Javadoc & algorithm reference added

✔ Tests included with full coverage

✔ All CI checks have passed

The branch is ready for review.
Whenever you get a chance, kindly take a look and provide feedback or approval.

Thank you for maintaining this project and your time 🙏

[duvvuvenkataramana]

@DenizAltunkapan Review and merge the PR