rmt: Add user context pointer for use with RMT translator callbacks (IDFGH-4135)

[outlandnish]

Overview

This is a continuation of #5919
This PR allows adds a temporary function signature, rmt_init_translator_with_context so that users can pass in a context pointer to use with rmt_write_sample. This is useful for situations when you need a reference to the RMT channel being used in the translator function (or other context like timing data for the RMT pulses).

Example

An example of this usage is shown in https://github.com/intentfulmotion/AddressableLED/blob/master/src/OneWireLED.cpp. In this example, timing data for different addressable LED strips are passed to the translation function. Since this object is dynamically created and the timing is not known at compile time, this gives the developer flexibilty to write a single translator callback for different timing usecases.

[Alvin1Zhang]

Thanks for your contribution.

[suda-morris]

Thanks @outlandnish this PR is in our internal review list now, will merge it as soon as possible 👍

[Alvin1Zhang]

Thanks for contribution, changes merged with 21bb6f2.