Skyimager WIFI Settings Bugs

Describe the bug Step 2 of the Skyimager enables the user to specify WIFI settings. There are various issues with using this functionality that should be fixed.

using the Reset button in the menu bar on the bottom does not reset these settings but simply minimizes the settings section.
deleting the settings via backspace/delete is not possible. Only workaround is to mark the content/right click select all and then use right click -> cut.
entering a long Wifi access point name or Wifi passcode breaks the image creation process with unspecific bug of boot parameter size

Environment information:

OS Ubuntu 20.04.2 LTS
Skyimager v0.2.0

Steps to Reproduce Steps to reproduce the behavior:

Open Skyimager
Go to Step 2 and enter Wifi credentials according to the bugs specified above
Click Next
See error

Actual behavior wifi_ssid wifi_passcode

Expected behavior

Options to delete the entered wifi SSID/passcode
Limitation on the Wifi SSID/passcode or a more precise error message.

skycoin / skybian

Skyimager WIFI Settings Bugs #100