Get: Enhance Get type to support dot-separated keys

[Emiyaaaaa]

Closes #1372

[sindresorhus]

Suggested change

	expectTypeOf<Get<Ambiguous, ['a.b'], NonStrict>>().toBeString();
	expectTypeOf<Get<Ambiguous, ['a.b'], NonStrict>>().toBeString();
	// Prefer the longest exact dotted key match when multiple dotted keys overlap
	type OverlappingDotKeys = {
	'a.b': string;
	'a.b.c': number;
	};
	expectTypeOf<Get<OverlappingDotKeys, 'a.b.c', NonStrict>>().toBeNumber();
	expectTypeOf<Get<OverlappingDotKeys, ['a.b.c'], NonStrict>>().toBeNumber();
	// Longer exact dotted key should continue resolving the remaining path
	type OverlappingDotKeysNested = {
	'a.b': {
	c: string;
	};
	'a.b.c': {
	d: boolean;
	};
	};
	expectTypeOf<Get<OverlappingDotKeysNested, 'a.b.c.d', NonStrict>>().toBeBoolean();
	expectTypeOf<Get<OverlappingDotKeysNested, ['a.b.c', 'd'], NonStrict>>().toBeBoolean();