[feature] setup profiler and don't bother to enable debug level log

[yyb196]

Signed-off-by: Frank Yang yyb196@gmail.com

Ⅰ. Describe what this PR did

In production environment i need to enable profilers like pprof stack dumping and gops always for the emergency cases or odd cases, in these cases i need to attach to the running pouchd to get the cpu memory or goroutine stack snapshot online, and then analyze why the odd things happen, but in these case we don't want alway print debug level log, which is too much output all the time.

This pr enables users to setup profilers and do not bother to always open debug log output. and if debug log level is specified, it's both enable debug level and setup profilers.

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how you did it

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #1111 into master will increase coverage by 0.84%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1111      +/-   ##
==========================================
+ Coverage    15.8%   16.65%   +0.84%     
==========================================
  Files         163      164       +1     
  Lines        8793     8846      +53     
==========================================
+ Hits         1390     1473      +83     
+ Misses       7300     7267      -33     
- Partials      103      106       +3

Impacted Files	Coverage Δ
client/client.go	31.03% <0%> (-8.36%)	⬇️
cli/cli.go	0% <0%> (ø)	⬆️
cli/command.go	0% <0%> (ø)
pkg/utils/utils.go	78.15% <0%> (+3.15%)	⬆️

[yyb196]

@allencloud @HusterWan please help to review this pr

[allencloud]

LGTM