Major frontend code cleanup (#452)

Many large changes, including:
- TypeScript enums are now string unions throughout
- Strong type-checking throughout the TS and Vue codebase
- Vue component props now all specify `as PropType<...>`
- Usage of annotated return types on all functions
- Sorting of JS import statements
- Explicit usage of Vue bind attribute function call arguments (`@click="foo"` is now `@click=(e) => foo(e)`)
- Much improved code quality related to the color picker
- Consistent camelCase Vue bind and v-model attributes
- Consistent Vue HTML attribute strings with single quotes
- Bug fix and clarity improvement with incorrect hint class parameters
- Empty Vue component objects like `props: {}` and `components: {}` removed

frontend/src/main.ts

@@ -9,7 +9,7 @@ import { initWasm } from "@/state/wasm-loader";
 
 import App from "@/App.vue";
 
-(async () => {
+(async (): Promise<void> => {
 	// Initialize the WASM editor backend
 	await initWasm();