v4.5.1 - Xcode 12 build compatibility

• fix(ios): depend directly on React-Core instead of transitively via React 1553a9f
• chore: yarn upgrade --latest f16aa78
• chore(CHANGELOG): prepare release notes for 4.5.1 6bd7205
• chore: update dependencies / refresh example 5cc07da
• chore: upgrade dependencies d8581e9

v4.5.0...v4.5.1