feat(bench): add tool pick table benchmark

[NamanJain8]

Add benchmark tool for picktable benchmarking:

Usage:
  badger benchmark picktable [flags]

Flags:
      --cpuprofile string   Write CPU profile to file.
  -h, --help                help for picktable
      --read-only           If true, DB will be opened in read only mode. (default true)
      --sample-size int     Sample size of keys to be used for lookup. (default 1000000)

Global Flags:
      --dir string        Directory where the LSM tree files are located. (required)
      --vlog-dir string   Directory where the value log files are located, if different from --dir

This change is 

[manishrjain]

Reviewed 4 of 4 files at r1.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @jarifibrahim and @NamanJain8)

---

badger/cmd/pick_table_bench.go, line 44 at r1 (raw file):

var (
	po = struct {

Rename to opts, or pickOpts

---

badger/cmd/pick_table_bench.go, line 93 at r1 (raw file):

// printKeyStats prints out the key size histogram.
func printKeyStats(db *badger.DB) {

This seems like it should belong to badger info.

[NamanJain8]

Reviewable status: 3 of 4 files reviewed, 2 unresolved discussions (waiting on @jarifibrahim and @manishrjain)

---

badger/cmd/pick_table_bench.go, line 44 at r1 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

Rename to opts, or pickOpts

Done.

---

badger/cmd/pick_table_bench.go, line 93 at r1 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

This seems like it should belong to badger info.

Thanks. Its already there in --histogram flag of badger info.