Add survey config and framework to show feature surveys to skaffold users.

[tejal29]

relates to #6166
Should merge after : #6186

In this PR, implement first 2 tasks mentioned in the design proposal.

1. Add survey.config struct to represent a survey
2. -id flag to skaffold survey command

==== Testing notes =====

➜  skaffold2 git:(add_surver_config) ✗ out/skaffold survey
Thank you for offering your feedback on Skaffold! Understanding your experiences and opinions helps us make Skaffold better for you and other users.

Skaffold will now attempt to open the survey in your default web browser. You may also manually open it using this URL:

https://forms.gle/BMTbGQXLWSdn7vEs6

Tip: To permanently disable the survey prompt, run:
   skaffold config set --survey --global disable-prompt true

➜  skaffold2 git:(add_surver_config) ✗ out/skaffold survey --id hats
Thank you for offering your feedback on Skaffold! Understanding your experiences and opinions helps us make Skaffold better for you and other users.

Skaffold will now attempt to open the survey in your default web browser. You may also manually open it using this URL:

https://forms.gle/BMTbGQXLWSdn7vEs6

Tip: To permanently disable the survey prompt, run:
   skaffold config set --survey --global disable-prompt true

➜  skaffold2 git:(add_surver_config) ✗ out/skaffold survey --id hats1
invalid survey id "hats1" - please enter one of [hats]
➜  skaffold2 git:(add_surver_config) ✗

[codecov]

Codecov Report

Merging #6185 (1b1471f) into master (62a01f6) will decrease coverage by 0.03%.
The diff coverage is 54.16%.

@@            Coverage Diff             @@
##           master    #6185      +/-   ##
==========================================
- Coverage   71.12%   71.08%   -0.04%     
==========================================
  Files         483      484       +1     
  Lines       21549    21589      +40     
==========================================
+ Hits        15326    15346      +20     
- Misses       5246     5262      +16     
- Partials      977      981       +4     

Impacted Files	Coverage Δ
pkg/skaffold/survey/survey.go	38.88% <11.11%> (-7.78%)	⬇️
cmd/skaffold/app/cmd/survey.go	70.00% <60.00%> (+12.85%)	⬆️
pkg/skaffold/survey/config.go	64.70% <64.70%> (ø)
pkg/skaffold/util/tar.go	52.87% <0.00%> (-4.60%)	⬇️
pkg/skaffold/docker/image.go	80.08% <0.00%> (-1.22%)	⬇️
pkg/skaffold/docker/parse.go	88.23% <0.00%> (+0.84%)	⬆️

---

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[briandealwis]

Given that this argument isn't used on other commands, we can just move this into NewCmdSurvey().

[tejal29]

done