• 🐛 FIX: missing memoization
• 👌 IMPROVE: Allowed Blocks = core/cover only

Major refactor 😎:

• Remove the need to have two custom blocks: Slider and Slide ("parent": ['wpe/slider]). This was just unnecessary and mildly confusing. We're ultimately utilizing InnerBlocks and useInnerBlocksProps() to nest things.
• Create constants.js to try and allow builders to drop in their own default blocks for slides.
• Generally "cleaner" codebase.