JSON read/write benchmarks

[SpencerTorres]

Summary

Closes #1474, see that thread for a breakdown of the results.

Output

goos: linux
goarch: amd64
pkg: github.com/ClickHouse/clickhouse-go/v2/benchmark
cpu: AMD Ryzen 9 7950X 16-Core Processor            
BenchmarkJSONInsert
BenchmarkJSONInsert/paths
BenchmarkJSONInsert/paths-32         	 5987515	       982.7 ns/op	    2408 B/op	      11 allocs/op
BenchmarkJSONInsert/structs
BenchmarkJSONInsert/structs-32       	 1620612	      3741 ns/op	    5437 B/op	      55 allocs/op
BenchmarkJSONInsert/marshal_strings
BenchmarkJSONInsert/marshal_strings-32         	 2864232	      2074 ns/op	    3473 B/op	      28 allocs/op
BenchmarkJSONInsert/strings
BenchmarkJSONInsert/strings-32                 	33972870	       150.6 ns/op	    2098 B/op	       2 allocs/op
BenchmarkJSONRead
BenchmarkJSONRead/paths
BenchmarkJSONRead/paths-32                     	 1385293	      4327 ns/op	    5411 B/op	     113 allocs/op
BenchmarkJSONRead/structs
BenchmarkJSONRead/structs-32                   	  971325	      6202 ns/op	    4697 B/op	     165 allocs/op
BenchmarkJSONRead/marshal_strings
    json_test.go:327: cannot receive JSON strings
--- SKIP: BenchmarkJSONRead/marshal_strings
BenchmarkJSONRead/strings
    json_test.go:331: cannot receive JSON strings
--- SKIP: BenchmarkJSONRead/strings
BenchmarkJSONMarshal
BenchmarkJSONMarshal/paths_direct
BenchmarkJSONMarshal/paths_direct-32           	  826999	      7351 ns/op	    4949 B/op	      86 allocs/op
BenchmarkJSONMarshal/paths
BenchmarkJSONMarshal/paths-32                  	  705961	      8643 ns/op	    5333 B/op	      87 allocs/op
BenchmarkJSONMarshal/structs
BenchmarkJSONMarshal/structs-32                	 2479334	      2389 ns/op	    1340 B/op	      26 allocs/op