Count app messages towards its authors for antispam

[almostSouji]

Currently, yuu cannot detect spam via user apps We could implement this by counting the message (content hash, occurrence) to the authorizing interaction owner

If an app posts multiple responses due to message limits this might have a considerable false positive rate - which should be much less (if at all) an issue in case of the content hash approach at least!

[iCrawl]

Done in 1d0d0fab8a5d7914278317a5c79d293bd9107b4d