Add new plugin unique, to check last messages

[8of]

Fixes #578

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[aahnik]

Thank you so much @8of for this PR! Sorry for the slow response... I would review and integrate it with my codebase as soon as possible.

[ExMalthus]

Thank you so much @8of for this PR! Sorry for the slow response... I would review and integrate it with my codebase as soon as possible.

Hi @aahnik, any progress with integrating this plugin? Looking forward to this sorely needed feature. Cheers!

[aahnik]

Sorry for the delays, I understand that this is a much needed feature, but i am unable to work on tgcf currently due to my current commitments.

I have a 3 mo summer break from May 6th, and I am looking forward to working on tgcf and popular feature requests.

You can expect this PR to get merged by 10th May.

Thank you so much for your contribution, and I again apologize for not being able to do justice this project.

[aahnik]

thank you so much for this contribution