Refactor code and drop deprecated parts

[robindemourat]

• remove BibliographyComponent (should be handled upstream)
• onAssetChange -> investigate removability
• assetRequestPosition -> investigate removability
• assets -> rename to something else ?
• handlePastedText -> onPastedText ?
• remove internal clipboard handling
• redundant blockAssetComponents
• drop spring system to an ease transition using d3-ease