Feature: Combining of single battery info event

[AvatarSD]

@gsuess
@EugeneSakun

Summary

This pull request enhances the TelemetryModule in the psdk_wrapper to improve battery state handling by introducing a fallback mechanism for publishing combined battery data when the primary battery info subscription fails. The changes ensure robust battery state reporting for dual-battery systems.

Changes

Header File Updates (telemetry.hpp):

• Added member variables and a utility function for combining battery states:
  • publish_combined_battery_state() to merge and publish data from both batteries.
  • Atomic flags (battery_info_subscription_failed_, has_battery1_info_, has_battery2_info_) to track subscription status and data availability.
  • Storage for latest battery info (last_battery1_info_, last_battery2_info_) with mutex protection (battery_info_mutex_).

Source File Updates (telemetry.cpp):

• Enhanced single_battery_index1_callback and single_battery_index2_callback:
  • Added error logging for failed publications.
  • Store latest battery info with mutex protection.
  • Trigger publish_combined_battery_state() when both batteries have data and the primary subscription has failed.
• Modified subscribe_psdk_topics() to set battery_info_subscription_failed_ based on the success of the DJI_FC_SUBSCRIPTION_TOPIC_BATTERY_INFO subscription.
• Implemented publish_combined_battery_state():
  • Combines data from both batteries (voltage, current, capacity, etc.) using the latest timestamp.
  • Publishes the combined state to the battery_pub_ topic.
  • Includes detailed debug logging for combined battery data.