Note that CA serial is ignored when randomizing. Fixes #14188
While here, when creating a CA, set the default serial to 1 since the GUI won't allow saving with the serial remaining at 0. That would otherwise force the user to change it themselves.
Related issues
Todo #14188: Add note to inform the user that the "Next Certificate Serial" value is ignored when the "Randomize Serial" option is enabled
Note that CA serial is ignored when randomizing. Fixes #14188
While here, when creating a CA, set the default serial to 1 since the
GUI won't allow saving with the serial remaining at 0. That would
otherwise force the user to change it themselves.