os.linux: Re-organize the KernelAnalysisModule

os.linux: Re-organize the KernelAnalysisModule

Bring the KernelAnalysis up to speed with regards to naming
conventions and public/internal separation:

- Rename KernelAnalysis to KernelAnalysisModule
- Move KernelStateProvider to internal package
- Move KernelStateProviderTest from lttng2 to os.linux plugin
- Remove direct references to KernelStateProvider in
  lttng2.kernel.core.tests, extend the analysis module instead
- Expose the internal package to the test plugin

Change-Id: I8a7baaacdc8a31c033e0fd8ae1650f34fd5232ae
Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-on: https://git.eclipse.org/r/46373
Reviewed-by: Hudson CI
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>