SHDP-243 Fix file rolling overwrite

- File naming strategies now can be initialised based on last file.
  i.e. rolling strategy can find a counter from where to continue.
- Flag telling if we can overwrite an existing file
- Fix to use multiple static naming parts.
  This allows to use static more like a static way in terms
  of using it before and after i.e. rolling part naming. As
  of now this static part can also be empty.
- better handling for naming paths
- Fixing tests due to file path concept changes