addItemOrDrop for mining ore

What has been done in this MR?

• Made mining ore use addItemOrDrop rather than addItem. Fixes loss of the additional ore obtained from a procced star sprite bonus if only one inventory slot was free. (Ask me how I learned of this bug, while in the basement of the Heroes' Guild.)
• Also correct the "rocks mined" attribute to take into account the second ore that you really did mine according to the message of the bonus proc.

What should testers check?

• Hand in 200 dust, then go mine some low-level ores with only one free inv spot. Observe that, when the effect triggers, the additional ore is dropped to the floor rather than being lost.
• Confirm with ::stats that the extra ore you mined now counts for the number of ores you mined
• Mining should otherwise not regress
• Please double check that I did not accidentally introduce an exploit to allow infinite powermining. In other words, if you mine a rock while having a full inv, you should be blocked with a message saying that you don't have enough inv space, in all cases under all circumstances.

• I have tested these changes thoroughly.
• I used the relevant Zaros tool for any JSON edits where possible, and have attached screenshots of any changes.