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`
