Introduce a 'BookmarkImporters' folder
Separate ImportedBookmark[Folder] into their own file
ImportedEntityList stores the imported entities.
Introduce ImportedBookmarksPreviewDialog UI
BookmarkImporter is teh importer!
Implemented BookmarkImporter::Initialize

and needed utility function in BookmarkManager
BmImporter also needs to query bookmark unique ids at init
ImportedBookmar(Folder) Ex_ fields assist importer
Need to lower case the url comparisons in BmImporter
A 'doubt' commit.
Implemented BookmarkImporter::Analyze
Update UI of ImportedBookmarksPreviewDialog

to match the current situation of importing bookmarks better.