JetBrains.Common.Timeline.DAL

Every time you change something in the format of the converted snapshot, increment this counter and update the gold in the `TimelineSnapshotVersionTests` test. The version is included in the name of the folder with the converted data. Such update will force a viewer to reprocess the snapshot, as it wouldn't be able to locate converted folder.

If some of the raw sections become obsolete - it should remain in the list so that it's id is not reused in the future. One can use ObsoleteSection tag for it to indicate this. Obsolete converted sections can be removed given TimelineConvertedSnapshotVersion.Version is updated