added is_alarm_active() function to check alarm is active or not

• Corrected comment typos: "allocated of not" to "allocated or not"
• Fixed logical error in alarms_control_is_fault_exists():
  • Return false when p_alarm is NULL (instead of true)
  • Updated misleading comment accordingly
• Added new function: alarms_control_is_alarm_active()
  • Validates pointer, index range, and allocated memory
  • Returns current alarm active state safely
• Added test cases too