broken: ext-panel's scrollable property

[fabriciomurta]

Found: Ext.NET 7.0.0-preview4_2020-07-13.

Sencha documentation: Ext.panel.Panel.scrollable - Ext JS 7.2.0 docs -- inherited from Ext.Component.Scrollable

Ext.NET 5 conveniently uses just an enum that maps as follows:

Enum Option	Client-side output
Both	true
Default	do not emit (use whatever default Ext JS has)
Disabled	false
Horizontal	"horizontal"
Vertical	"vertical"

The way it is with Ext.NET 7 aside of not accepting the values Ext.NET 5 used to, it is really confusing what to choose from intellisense: from the property accepted types perspective:

from possible input perspective (list is gigantic):

In this case it would be really nice to force a simple enum to allow selection.

As a workaround for this, just input from the enum in Ext.NET 5, the values it would output instead. For instance, scrollable="Both" => scrollable="true".