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/App.vue

@@ -221,16 +221,16 @@ img {
 <script lang="ts">
 import { defineComponent } from "vue";
 
-import { DialogState, createDialogState } from "@/state/dialog";
+import { createAutoSaveManager } from "@/lifetime/auto-save";
+import { initErrorHandling } from "@/lifetime/errors";
+import { createInputManager, InputManager } from "@/lifetime/input";
+import { createDialogState, DialogState } from "@/state/dialog";
 import { createDocumentsState, DocumentsState } from "@/state/documents";
 import { createFullscreenState, FullscreenState } from "@/state/fullscreen";
-
-import MainWindow from "@/components/window/MainWindow.vue";
-import LayoutRow from "@/components/layout/LayoutRow.vue";
 import { createEditorState, EditorState } from "@/state/wasm-loader";
-import { createInputManager, InputManager } from "@/lifetime/input";
-import { initErrorHandling } from "@/lifetime/errors";
-import { createAutoSaveManager } from "@/lifetime/auto-save";
+
+import LayoutRow from "@/components/layout/LayoutRow.vue";
+import MainWindow from "@/components/window/MainWindow.vue";
 
 // Vue injects don't play well with TypeScript, and all injects will show up as `any`. As a workaround, we can define these types.
 declare module "@vue/runtime-core" {