[FEATURE] remove PeakType template argument from FeatureFinder

This pull request removes the template argument from FeatureFinder and related classes. See #1119 for the motivation. So far I didn't see the FF crash on travis for this branch so it seems likely that this fixes this issue. 

Since I still received some time outs on travis I added some include-what-you-use commits, that cleanup the includes of some of the core classes of OpenMS. I'm not sure if we should add this to this pull request but, I wanted to test if it further improves the compile time and yes, it does. A short test running `time make all -j14` gave the following numbers on `develop` and this branch.

```
develop
real  10m23.640s
user  124m9.062s
sys 8m19.019s
```

and 

```
feature/remove-template-from-featurefinder
real  9m51.046s
user  116m31.389s
sys 7m58.314s

```

STL before own stuff? Should be imho other way around. Is this an artefact of IWYN?