Statistic for JobManager

#### Steps to Reproduce
1. Currently nothing, cause no function
2.
3.

#### What I Expected

#### What Happened Instead

#### WordPress / WP Job Manager Version
5.1.1/ 3.2.2

#### Browser / OS Version

#### Screenshot / Video

#### Context / Source

It would be great if the Job Manager has a function to have statistics for each listing a customer has postet. So that the customer is able to see how many click his listing has and how may applications have ben send and so on.
And the statistic count has to set to zero, when a customer relists a listing.
Maybe this could be based on google analytics code in some way, cause normaly every site is runnig this.

No files, tests, or entry points are named in the issue, so first clarify the required listing statistics, how clicks and applications are counted, whether Google Analytics is involved, and when relisting resets totals. Done should mean customers can view the agreed metrics for their listings and relisting reliably sets the relevant counts to zero.

Written by the indexing model from the issue text.