Rewrite stats summary post to golang

[mhoppa]

What does this PR (Pull Request) do?

• This PR does not have a related issue

Rewrite /stats_summary/create into a new route of /stats_summary

Which Traffic Control components are affected by this PR?

• Documentation
• Traffic Control Client
• Traffic Ops
• Traffic Stats

What is the best way to verify this PR?

If this is a bug fix, what versions of Traffic Control are affected?

The following criteria are ALL met by this PR

• This PR includes tests OR I have explained why tests are unnecessary
• This PR includes documentation OR I have explained why documentation is unnecessary
• This PR includes an update to CHANGELOG.md OR such an update is not necessary
• This PR includes any and all required license headers
• This PR ensures that database migration sequence is correct OR this PR does not include a database migration
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

Additional Information

[asf-ci]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/trafficcontrol-PR/4883/

[mhoppa]

@ocket8888 once you get a chance can you re review?? :)

[ocket8888]

All of the actual code and docs changes look fine, but if this is going to close #3833 then it needs to either rewrite or deprecate summary_stats/create (and I'm pretty sure we want the latter). Which would mean a patch in the Perl handler to return a deprecation notice and a line in the CHANGELOG. If you wanna do that in a separate PR that's fine, but then this doesn't close #3833.

[mhoppa]

#4186 already posted waiting for this to merge let me remove the issue from the pull request template so it doesnt close it

[ocket8888]

Manual tests confirm it works according to the docs which build without errors or warnings and look fine, all unit and api/client integration tests passing.