perf: avoid unnecessary byteslice->string before fmt %s verb (#10364)

fmt.Printf or fmt.Sprintf already know how to convert a
byteslice into a string when building the output; we shouldn't
incur the unnecessary string(byteslice) conversion.
Using Bencher, we can see improvements such as
https://dashboard.github.orijtech.com/benchmark/3245b8e4bbbd44a597480319aaa4b9fe
which in independent experiments show:

* time/op (ns/op)
FormatIt-8	1.2µs ± 2%	1.1µs ± 10%	-11.77%	(p=0.000 n=10+9)

* speed (MB/s)
FormatIt-8	0.71GB/s ± 2%	0.80GB/s ± 9%	+13.59%	(p=0.000 n=10+9)

* allocs/op (B/op)
FormatIt-8	2.0kB ± 0%	1.1kB ± 0%	-45.62%	(p=0.000 n=10+10)

* allocs/op (count/op)
FormatIt-8	11 ± 0%	        9.0 ± 0%	-18.18%	(p=0.000 n=10+10)

Fixes #10363

x/capability/simulation/decoder.go

@@ -27,7 +27,7 @@ func NewDecodeStore(cdc codec.Codec) func(kvA, kvB kv.Pair) string {
 			return fmt.Sprintf("CapabilityOwners A: %v\nCapabilityOwners B: %v\n", capOwnersA, capOwnersB)
 
 		default:
-			panic(fmt.Sprintf("invalid %s key prefix %X (%s)", types.ModuleName, kvA.Key, string(kvA.Key)))
+			panic(fmt.Sprintf("invalid %s key prefix %X (%s)", types.ModuleName, kvA.Key, kvA.Key))
 		}
 	}
 }