#53 feat: add distinct operator and tests

[ProdigSun]

Hi! I tried solving the issue #53 like this :)

[jcornaz]

Hi,

Thank you very much for the contribution :-)

Sadly, I decided to discontinue this project. This is a combination of multiple factors, including (but not limited to):

• A shift of interests from my side
• An new increased complexity of publishing (since the jcenter is gone)
• Kotest became a very good alternative for property based testing with Kotlin

@RafaPili1 I'm thankfull for your contribution, and I'm sorry to disapoint you by discontinuing the project and not merging this PR.