To add Implementation of Base64 Algorithm (#6586)

* feat: base64 algorithm implementation

* feat: test coverage implementation of Base64Test.java

* Update DIRECTORY.md

* fix: build and lint fix update

* patch: linter fix

* fix: enforce strict RFC 4648 compliance in Base64 decoding

* fix: enforce strict rfc 4648 compliance in base64 decoding

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Co-authored-by: Oleksandr Klymenko <alexanderklmn@gmail.com>