Move low-level version to new block and add high-level version

Add a block to rename all keys from `metadata.version` to `metadata.version.lowlevel`. Additionally add a new block `metadata.version.highlevel` which contains the same information but for the `streaming_extractor_music_svm` binary.

The default yamloutput module automatically adds a key `metadata.version.essentia` to all things that it writes. This would have been additional data that we already have in the highlevel block, so I made this a preference, with a default of `true`.
It does not affect the lowlevel extractor because this data was already written in `MusicExtractor::compute`