Refactor CollectorConfig

Changes done:
- Remove InitCollectorConfig and replace it with a proper constructor.
- Delete default constructor.
- Created multiple helper methods in order to split initialization
  of the configuration.
- Inlined several simple getters and setters for consistency.
- Removed static constexpr variables that could be directly applied as
  default member initializers.
- Replaced const char*[] with std::array.

Author: Molter73

collector/collector.cpp

@@ -136,8 +136,7 @@ int main(int argc, char** argv) {
     CLOG(FATAL) << "Error parsing arguments";
   }
 
-  CollectorConfig config;
-  config.InitCollectorConfig(args);
+  CollectorConfig config(args);
 
   setCoreDumpLimit(config.IsCoreDumpEnabled());