IMetadataServiceCb: Add a virtual destructor
VLCMetadata tests: Avoid a potentially invalid read after call to SetUp from the test case
Metadata: Release all meta obtained from VLC
test: Fix build
File: Add a Ready flag to signal metadata collection completion
VLC service: Add cleanup
tests: VLC service: Fail early if libvlc fails to load
media library: Do not start parsing automatically
Rewrite IMetadataService code

Processing is done by a threadpool (limited to a single thread so far)
This will allow using asynchronous modules one after another
Fixing VLC service cleaup code
Use libvlcpp instead of raw C libvlc
Implement parseVideoFile
CMakeFiles: minor tweaks

Remove forced debug flag, let cmake add it if we build in debug mode
Add pedantic warning flag
Parser: Fix uninitialized value
Parser: Use atomic bool
VLCMetadataService: Expose FPS
Add a video file tracks parsing test