Fixing memory cleanup on Wire instance

Summary

The constructor doesn't cleanup memory for a wire instance.

Issues could happen, such as wrong initialization.

This PR fixes/implements the followingbugs/features

• Issue on locked/bad allocated i2c on turning on

Example of bad behaviour using a STM32F411 and an APDS9960 sensor:

#include"Arduino_APDS9960.h"APDS9960 * apds;TwoWire * wire;voidsetup() {  Serial.begin(115200);  wire=newTwoWire(PB7,PB8);  wire->begin();  apds =newAPDS9960(*wire,PC10);  apds->begin();}voidloop() {if (apds->proximityAvailable()) {int value = apds->readProximity();    Serial.println(value);  }}

The bad behaviour is that after turn off and on the board, wire locks.
Note: it works if you go from boot mode to running mode

This pull request solve this issue adding the following line in TwoWire constructors.

memset((void*)&_i2c, 0, sizeof(_i2c));