Enable Typescript noImplicitThis (#33250)

- Enable https://www.typescriptlang.org/tsconfig/#noImplicitThis
- Wrap Vue Template-Syntax SFCs in
[`defineComponent`](https://vuejs.org/api/general#definecomponent) which
makes type inference and linter work better
- Move `createApp` calls outside the SFCs into separate files
- Use [`PropType`](https://vuejs.org/api/utility-types#proptype-t) where
appropriate
- Some top-level component properties changed order as dictated by the
linter
- Fix all tsc and lint issues that popped up during these refactors

web_src/js/components/DiffFileTreeItem.vue

@@ -25,7 +25,7 @@ defineProps<{
 const store = diffTreeStore();
 const collapsed = ref(false);
 
-function getIconForDiffType(pType) {
+function getIconForDiffType(pType: number) {
   const diffTypes = {
     1: {name: 'octicon-diff-added', classes: ['text', 'green']},
     2: {name: 'octicon-diff-modified', classes: ['text', 'yellow']},
@@ -36,7 +36,7 @@ function getIconForDiffType(pType) {
   return diffTypes[pType];
 }
 
-function fileIcon(file) {
+function fileIcon(file: File) {
   if (file.IsSubmodule) {
     return 'octicon-file-submodule';
   }