"True" (non-statically-analyzable) dynamic imports

### What problem are you trying to solve?

Separate tracking issue for non-statically-analyzable dynamic imports, as [the fix](https://deno.com/deploy/changelog#statically-analyzable-dynamic-imports) for [#1 Dynamic imports](https://github.com/denoland/deploy_feedback/issues/1) only solves statically-analyzable use cases.

Among other use cases, this would be useful for framework authors wishing to skip build steps entirely; without this feature, at a minimum, a file containing literal paths for routes/components has to be generated.

Example (currently possible in Deno, but not on Deno Deploy):

```ts
import { serve } from 'https://deno.land/std@0.190.0/http/server.ts'
import { resolve } from 'https://deno.land/std@0.190.0/path/mod.ts'
import html from 'https://deno.land/x/htm@0.2.1/mod.ts'

serve(async (req: Request) => {
try {
const { default: route } = await import(
resolve('./routes', `.${new URL(req.url).pathname}.tsx`),
)

return html({ body: route({ req }) })
} catch (e) {
if (e.code === 'ERR_MODULE_NOT_FOUND') {
return new Response(null, { status: 404 })
} else throw e
}
})
```

### Describe the solution you'd like

* True dynamic local path/URL imports to be available in Deploy, supporting js/ts/jsx/tsx/json (via `{ assert: { type: 'json' } }`) file types (is this list exhaustive?)
* Dynamic non-local URL imports — not sure how much demand there is for this, but it'd be nice to have full feature parity with Deno.
* On-the-fly SWC transpilation of dynamically imported ts/tsx/jsx files, falling back to the current eszip-based solution for statically analyzable paths/URLs for better performance.

### Describe alternatives you've considered

A partial solution could involve only supporting js/json files, with transpilation not supported. However, my guess is that wouldn't support most use cases, as most developers using Deno primarily author in TypeScript.

### Documentation, Adoption, Migration Strategy

_No response_