Fix issue due to repeated status()/connected() call

[giulcioffi]

When a sketch repeatedly calls client.status() and client.connected() functions, the connection occasionally gets stuck.
This issue had already been address by PR #50 ,which was then reverted thinking that its functionality was already covered by further code modifications.
Unfortunately it still seems to be needed.
A further modification has been introduce to let the driver correctly detect a client disconnection. In order to avoid lockups, we need to call available() function. This function, calling lwip_ioctl_r(), returns the number of bytes of pending data already received in the socket’s network. At most the result is 0. However, available() is never able to detect a network disconnection.
peek() , on the other hand, is the function to call to receive data with lwip_recv_r(). This function can actually return an error if the connection went down.
The procedure adopted here is to check if there are already available data and, if not, try to read from the network. In this way we avoid lockups by always checking if there are already available data before trying to receive new ones and we are also able to detect a disconnection.

[aentinger]

Firmware for NINA-W102 for Arduino Nano RP2040 Connect:
NINA_W102-PR-73-Nano-RP2040-Connect.zip

[aentinger]

OTA works for Nano RP2040 Connect.

[pennam]

OTA works also on MKR WIFI 1010

[aentinger]

OTA works also on MKR WIFI 1010

Thank you 👍 🤗