Alternative Improve _uploadReadByte (#2656)

* add opportunity for more than one retry to _uploadReadByte

* an alternative timeout-based method to making _uploadReadByte more resilient

* move timing variables in the correct scope

* implement and use client.getTimeout instead of hard-coded timeout in _uploadReadByte

* add missing return

* some refactoring to address respecting the timeout in a potentially deadlocked connection

* fix spelling in comment

* address review comments; move impl to cpp file for getTimeout, and remove local variable for currentMillis

* remove redundant cast

* need to check for timeout outside the inner while as well

* update WebUpdate example to print something in unexpected callback condition

* update log_e messages per review comments

cores/esp32/Stream.cpp

@@ -82,6 +82,9 @@ void Stream::setTimeout(unsigned long timeout)  // sets the maximum number of mi
 {
     _timeout = timeout;
 }
+unsigned long Stream::getTimeout(void) {
+  return _timeout;
+}
 
 // find returns true if the target string is found
 bool Stream::find(const char *target)