Support for emoji reactions

ref: pleroma-meta#4 (closed)

api: https://docs-develop.pleroma.social/backend/API/pleroma_api/#post-apiv1pleromastatusesidunreact_with_emoji

changed the description

mentioned in issue pleroma-meta#16 (closed)

assigned to @shpuld

Will post design tests and mocks here as I go

I'm somewhat certain this has been done :)

closed