Upgrade TypeScript, Storybook and Prettier

[axelboc]

TypeScript 4.6

• Control Flow Analysis for Destructured Discriminated Unions - may help us write cleaner code in some places, but difficult to identify where at this point.

TypeScript 4.7

• Go to Source Definition - finally!! This command takes you to the actual source code of a method, object or whatever, instead of to its type declaration! You can access the command after upgrading VSCode, by right-clicking on something in the editor or via the command palette. Ctrl+click still takes you to the type declaration.
• Instantiation Expressions - this is a really cool feature that we may be able to benefit from in the future:

interface Box<T> {
    value: T;
}

function makeBox<T>(value: T): Box<T> {
    return { value };
}

// BEFORE
function makeHammerBox(hammer: Hammer) {
    return makeBox(hammer);
}
// or...
const makeWrenchBox: (wrench: Wrench) => Box<Wrench> = makeBox;

// AFTER
const makeHammerBox = makeBox<Hammer>;
const makeWrenchBox = makeBox<Wrench>;

// Also works for Array, Map, Set:
const ErrorMap = Map<string, Error>;
const errorMap = new ErrorMap(); // instead of `new Map<string, Error>()`

• Optional Variance Annotations for Type Parameters - I doubt we'll ever need to use those, but it's good to know this new syntax exists
• extends Constraints on infer Type Variables - same, good to know

Storybook 6.5

• Brings support for React 18, so it will make upgrading easier.
• At last, the UI has buttons to open/close the controls panel 🎉
• The bug that navigated back to the first page when changing the value of a control seems to be fixed 🎉
• I've enabled the new webpack 5 builder with caching and lazy compilation, which speeds up starting the Storybook significantly 🎉
• There's also an experimental Vite builder, but apparently it's not faster than webpack 5 with lazy compilation.
• I tried enabling experimental support for MDX v2, but it broke our markdown tables and I wasn't sure how to bring them back, so I gave up.
• The auto-generated titles of the stories now have spaces:
  

Prettier 2.7

• Brings a new --cache CLI option that speeds things up condierably 🎉