Rename Item#onStackClicked for clearer distinction

[Phoupraw]

Item#onStackClicked is not able to be distinguished clearly from Item#onClicked. Users have to read their doc for clearer distinction (however, their doc seems not enough unclear, either.)

"onStackClicked" sounds to seem to an event that the item stack itself is clicked but not that the item stack clicks another item stack. Especially when comparing with "onClicked", they are more confusing.

So I suggest that the word "click" shouldn't be past participle but should be basic form or third-person singular; the word "on" should be placed behind "click". For example, "clickOnOther".