Automatically end concentration when all summoned creatures are dead

If we have more characters capable of summoning the same creatures (like a Ranger and Greenmage in the same party using Conjure Animal) it can be hard to keep track of which summons belong to what character. This is important information because I would like the option to cast new concentration spells without having to gamble on whose summoned creatures have been killed, risking removing summons I want to keep on the board.

Alternatively, adding the summoner's name to the name of the summon could work to let us manually double check.

"[character first name]'s Conjured Beast"

"Bob's Conjured Beast"