Hi,
When creating a standard Joomla plugin, form fields can use the `showon` attribute to create conditional fields. This is very useful for organizing settings, because some options are only relevant when another field has a specific value.
For example:
```xml
<field name="mode" type="list" label="Mode">
<option value="simple">Simple</option>
<option value="advanced">Advanced</option>
</field>
<field name="advanced_option"
type="text"
label="Advanced Option"
showon="mode:advanced" />
```
In this case, the "Advanced Option" field is only displayed when the mode is set to "Advanced".
However, when creating VirtueMart plugins (for example `vmpayment` or `vmshipment` plugins), the fields defined in <vmconfig> do not seem to support the `showon` attribute.
Would it be possible to add support for Joomla's native `showon` functionality in VirtueMart plugin configuration forms?
I think it would make plugin settings much cleaner and easier to organize, especially for plugins with many configuration options.
Thank you.