Add ChaCha32Arduino library

[regimantas]

Adds a lightweight Arduino-compatible implementation of the 32-round ChaCha stream cipher. Repository: https://github.com/regimantas/ChaCha32Arduino

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/regimantas/ChaCha32Arduino:

Linting library in ChaCha32Arduino
WARNING: Invalid category field value Encryption in library.properties                                         
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format
         (Rule LP038)                                                                                          

Linter results for project: 0 ERRORS, 1 WARNINGS

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Linting sketch in ChaCha32Arduino/examples/BasicUsage

Linter results for project: no errors or warnings

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Linter results for projects: 0 ERRORS, 1 WARNINGS

[github-actions]

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