Unify extension debug printing

[arturbosch]

Unfortunately letting RuleSetProvider extend Extension is not backwards compatible.

[codecov]

Codecov Report

Merging #2770 into master will decrease coverage by 0.03%.
The diff coverage is 50.00%.

@@             Coverage Diff              @@
##             master    #2770      +/-   ##
============================================
- Coverage     80.53%   80.49%   -0.04%     
  Complexity     2319     2319              
============================================
  Files           385      385              
  Lines          6961     6957       -4     
  Branches       1261     1261              
============================================
- Hits           5606     5600       -6     
- Misses          727      728       +1     
- Partials        628      629       +1     

Impacted Files	Coverage Δ	Complexity Δ
...otlin/io/gitlab/arturbosch/detekt/api/Extension.kt	100.00% <ø> (ø)	0.00 <0.00> (ø)
...itlab/arturbosch/detekt/core/extensions/Loading.kt	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...io/gitlab/arturbosch/detekt/core/RuleSetLocator.kt	83.33% <66.66%> (-16.67%)	6.00 <3.00> (ø)
...lab/arturbosch/detekt/core/FileProcessorLocator.kt	100.00% <100.00%> (ø)	5.00 <0.00> (ø)

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