Make GetBPRegInfo take pointers to two std::strings for the name and description now.

Kills off the requirement of passing sizes in. This also lets us kill off snprintf calls and replace them with StringFromFormat.
Fix typos in BP defines in BPMemory.h.

BPMEM_DISPLAYCOPYFILER -> BPMEM_DISPLAYCOPYFILTER
BPMEM_TX_SETLUT_4 -> BPMEM_TX_SETTLUT_4
Add all BP regs to the switch statement in GetBPRegInfo.

Makes the FIFO player's Analyze page more informative in terms of
providing the names for some commands. Descriptions are still needed however.