Drawer needs the following updates for its inline variant to support glass theme:

• opt-in modifier for plain/no background

• opt-out modifier for not-plain/background

• automatic opt-in to plain styling when in a glass container & when glass theme is applied, unless opt-out is specified

• opt-in modifier for glass styles (with pill shape)

Figma link:
https://www.figma.com/design/qRn3S225WwGHIdgGZX0LTC/Unified-Theme--Design-Tokens--Styles---Specs?node-id=10328-3751&m=dev

The scenario where a glass modifier would be applied to an inline drawer is the following:

Jira Issue: PF-3523