Since having it inlined makes the query a bit easier to read. We
obviously need to share it if we want to share this predicate, but for
now that does not seem to be the case.
This was slightly messier than anticipated, as I hadn't accounted for
the dozen uses of `startInAttr` in our codebase. To circumvent this,
I decided to put the type tracking implementation in the `internal`
directory, and wrap it with a file that ensures the old interface still
works.
Since we want to be able to easy select request-handlers that are not
set up as part of a view-class, we need to easily be able to identify
those. To handle cases like the one below, we _can't_ just define these
to be all the async functions that are not methods on a class :(
```py
# see https://docs.aiohttp.org/en/stable/web_quickstart.html#organizing-handlers-in-classes
class MyCustomHandlerClass:
async def foo_handler(self, request): # $ MISSING: requestHandler
return web.Response(text="MyCustomHandlerClass.foo")
my_custom_handler = MyCustomHandlerClass()
app.router.add_get("/MyCustomHandlerClass/foo", my_custom_handler.foo_handler) # $ routeSetup="/MyCustomHandlerClass/foo"
```
So it seemed easiest to narrow down the route-setups, but that means we
want both refinement and extensibility... so `::Range` pattern to the
rescue 🎉
The important piece of code that still works after this commit, but
which hasn't been changed, is the one below:
```codeql
/**
* A parameter that will receive a `aiohttp.web.Request` instance when a request
* handler is invoked.
*/
class AiohttpRequestHandlerRequestParam extends Request::InstanceSource, RemoteFlowSource::Range,
DataFlow::ParameterNode {
AiohttpRequestHandlerRequestParam() {
exists(Function requestHandler |
requestHandler = any(AiohttpCoroutineRouteSetup setup).getARequestHandler() and
```
