WiFiStorage read/write operations ignore return value from WiFiDrv

[mikaelj]

....making it impossible to know if the operation was successful or not.

e.g. WifiStorage.write():

WiFiNINA/src/WiFiStorage.h

Line 53 in 0e7e65b

static bool write(const char *filename, uint32_t offset, uint8_t* buffer, uint32_t buffer_len) {

What's the recommended way of catching write errors?

Also, return type is int8_t while buffer_len is uint32_t.