feat: route intent preloading (#102574)

This PR adds preloading to internal links. To do this, we:

- expose a new `preload` function from `makeLazyLoadComponent`
- attach this method to the route’s `handle`
- invoke the `preload` method on hover / focus of our `<Link>` component
if the Link would go to a route

Note:

- we attach the hover / focus event handlers to _all_ Links, but they
will trigger the promise only once because it’s cached.
- if a route was made without `makeLazyLoadComponent`, it won’t have a
preload function so nothing happens.
- only static assets are preloaded - not data calls

This should ensure that navigations between routes, when going there the
first time, are faster and we don’t have to show loading spinners that
often. Combined with [deferring the fallback for lazy loaded
files](#102031), we should get a
smooth ux for first navigations.

before (notice the big spinner in the middle of the page on each
navigation):
after (notice the big spinner in the middle of the page is gone):

Author: TkDodo

static/app/main.tsx

@@ -9,6 +9,7 @@ import {CommandPaletteProvider} from 'sentry/components/commandPalette/context';
 import {FrontendVersionProvider} from 'sentry/components/frontendVersionContext';
 import {ThemeAndStyleProvider} from 'sentry/components/themeAndStyleProvider';
 import {SENTRY_RELEASE_VERSION, USE_REACT_QUERY_DEVTOOL} from 'sentry/constants';
+import {RouteConfigProvider} from 'sentry/router/routeConfigContext';
 import {routes} from 'sentry/router/routes';
 import {DANGEROUS_SET_REACT_ROUTER_6_HISTORY} from 'sentry/utils/browserHistory';
 
@@ -29,7 +30,9 @@ function Main() {
         <ThemeAndStyleProvider>
           <NuqsAdapter defaultOptions={{shallow: false}}>
             <CommandPaletteProvider>
-              <RouterProvider router={router} />
+              <RouteConfigProvider value={router.routes}>
+                <RouterProvider router={router} />
+              </RouteConfigProvider>
             </CommandPaletteProvider>
           </NuqsAdapter>
           {USE_REACT_QUERY_DEVTOOL && (