Upgrade Storybook to v7

[rushi]

• 🎉 Upgrade to Storybook v7
• Add tailwindMerge and created cn utility function

Features of Storybook v7

These are the features of v7 that affect our UI Kit:

1. We can use vite for Storybook so we no longer have to use Webpack. This makes start/stop much faster. This also makes future migration to TS easier.
2. It uses the new Component Story Format v3 which makes it much easier to write stories. The amount of code we need to write a story has dropped quite a bit
3. We have more flexibility in hiding & showing certain feature sets per components
4. Auto-docs functionality means we don't have to manually write out all the props in the stories
5. Table of contents for the larger docs pages.
6. Play functions: They allow us to interact with components without needing user interaction. For example fill out forms, click buttons.