On wrongly formatted input file provide line number and more descriptive message

[kamran-redis]

In current version the message for wrongly formatted CSV line is opaque , provide line number and value number to trouble shoot easily.
Current message does not help

panic: runtime error: index out of range [5] with length 5

goroutine 114 [running]:
main.preProcessCmd(0xc000a08100, 0xf4, 0xc000276201, 0xc0009ffa70, 0x4, 0xc0009ffa74, 0x2, 0xc0009ffa77, 0xb, 0xc000b119c0, ...)
	/root/ftsb/cmd/ftsb_redisearch/cmd_processor.go:223 +0x5ef
main.connectionProcessor(0xc000130080, 0xc000012190, 0x0)
	/root/ftsb/cmd/ftsb_redisearch/cmd_processor.go:88 +0x9ef
created by main.(*processor).ProcessBatch
	/root/ftsb/cmd/ftsb_redisearch/cmd_processor.go:186 +0x1a6