Improve batch analysis behavior

[firewave]

Currently the batch analysis is just a batch of on-the-fly inspections. So if you pass a folder to it you will get different results as if you passed a folder to Cppcheck.

We are also ignoring findings on header (.h) files which are reported while analyzing a source file. These findings need to be reported in the batch analysis as well.

[firewave]

It seems if you select a folder it will process the whole folder on the filesystem and not just the project files in that folder which may lead to unexpected findings being reported.