[Grbl_Esp32 PR#202] Upload error improvement and bug fixes

Fix update partition size in [ESP420]
add upload file size checking
better upload error management
use grbl version + build version for better tracking
new embedded page from 3.0
– display fw version
– menu link link to wiki / github
– auto detection of index.html.gz when uploaded
– websocket to limit to one instance
– build batch to generate page and fw file
fix for Apple captive portal blocking websocket
Change Error 0 message to No connection