Need heuristic-based LRO helper for ARM crates

LROs in ARM TypeSpecs don't always have all the information we need available to generate the right code for polling LROs. Instead, we should add support to `azure_core` only for ARM crates identified by the emitter to use that basically works like Go's:

* https://github.com/Azure/azure-sdk-for-go/blob/main/sdk/azcore/runtime/poller.go - specifically the `NewPoller` functions ->
* https://github.com/Azure/azure-sdk-for-go/tree/main/sdk/azcore/internal/pollers which, for ARM, uses
* async
* body
* loc

Python's is worth looking at as well: https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-mgmt-core/azure/mgmt/core/polling/arm_polling.py

We could a new public `resource_manager` module under `azure_core::http::poller` that contains a function named `new_poller` that takes the type parameters and function parameters necessary to create a heuristic-based poller like the examples above (using functions in Rust as much as possible, instead of different structs with different implementations like in Go) and in [`CertificateClient::begin_create_certificate()`](https://github.com/Azure/azure-sdk-for-rust/blob/1f5abd74e6da08daed423d124d7aaf12dfcd0da3/sdk/keyvault/azure_security_keyvault_certificates/src/clients.rs#L149). It should also take an `Option` to support, among other things, continuation, as explained in [poller.rs](https://github.com/Azure/azure-sdk-for-rust/blob/main/sdk/core/azure_core/src/http/poller.rs).