Feat/parameters

[Bridiro]

Purpose

This pull request introduces several API and structural improvements to the steering wheel firmware, focusing on modularity, clarity, and future extensibility. The main themes are a refactor of the inputs handling API, the introduction of a new parameters management module, and enhancements to the LED control interface. These changes clarify callback responsibilities, make the codebase more hardware-agnostic, and improve documentation for easier integration and maintenance.

Overview

1. The inputs-api interface is redesigned to use explicit callbacks for button press, long-press, release, and knob rotation events, replacing the previous generic notify/action callbacks.
2. A new hardware-agnostic parameters API is introduced (parameters-api.h and parameters.h), providing a single source of truth for user-facing tunable parameters (e.g., power, regen, PTT). It supports both input-driven and external updates, and broadcasts changes via a registered callback.
3. New API functions leds_api_save_pattern and leds_api_restore_pattern are added, allowing the current LED state to be snapshotted and restored (useful for temporary overlays like PTT). The handler structure is updated with a backup buffer.

Guidance

Mainly check the parameters module as it's the focus of the PR, but also check events, leds and inputs (both on CM4 and CM7) as most of the code changed to accommodate the new module.

[Tonidotpy]

• In general avoid shortening names if it is not a convention of some sort (i.e. use button instead of btn, callback instead of cb, etc...). This way there is no ambiguity of what the identifier represent
• Remember to add a prefix with the filename before any identifier in the module
• There is no test for the popup module

[Tonidotpy]

Not much to change