Following the same criteria for PLANET-4534, find out which portions of the JS we can split and possibly defer. Consider the option of adding an entry point to Webpack for each block, checkout GPNL's work in the [same direction|https://github.com/greenpeace/planet4-gpnl-plugin-gutenberg-blocks/blob/08328f26500bb8abc3faf638b687035e6c00be60/p4-webpack-config.js#L15

Ticket re-purposed to map the initial work done and splitting the Timeline block