Move code to new Coverage plugin

[uhafner]

There is a lot of old and deprecated code in this plugin. Additionally, some steps have been deprecated. In order to simplify future development, it makes sense to split the code into two plugins. This is similar to the split of the old and deprecated warnings plugin into the new warnings next generation plugin.

The new code will be placed into the new Jenkins Coverage plugin.

[codecov]

Codecov Report

Merging #795 (0514f0d) into master (9d6fbe3) will decrease coverage by 1.73%.
The diff coverage is n/a.

❗ Current head 0514f0d differs from pull request most recent head fd1b6a2. Consider uploading reports for the commit fd1b6a2 to get more accurate results

@@             Coverage Diff              @@
##             master     #795      +/-   ##
============================================
- Coverage     74.58%   72.86%   -1.73%     
+ Complexity     1754     1032     -722     
============================================
  Files           135       88      -47     
  Lines          6394     3825    -2569     
  Branches        688      440     -248     
============================================
- Hits           4769     2787    -1982     
+ Misses         1400      892     -508     
+ Partials        225      146      -79     

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more