Identify more labels, and use the jumptable macro when possible

engine/printer/printer_serial.asm

@@ -16,16 +16,7 @@ Printer_StartTransmission:
 	ret
 
 PrinterJumptableIteration:
-	ld a, [wJumptableIndex]
-	ld e, a
-	ld d, 0
-	ld hl, .Jumptable
-	add hl, de
-	add hl, de
-	ld a, [hli]
-	ld h, [hl]
-	ld l, a
-	jp hl
+	jumptable .Jumptable, wJumptableIndex
 
 .Jumptable:
 	dw Print_InitPrinterHandshake ; 00