Add additional XL size for S2 Dialog

[synox]

Provide a general summary of the feature here

We needs an additional Dialog size

🤔 Expected Behavior?

Dialogs of width ~944px (we can agree on the exact number) are supported

😯 Current Behavior

Only S, M, and L are supported. None of the is large enough for our use cases, and full screen does not work well in this use case.

💁 Possible Solution

No response

🔦 Context

Needed for our larger dialogs

💻 Examples

No response

🧢 Your Company/Team

Adobe/GenStudio

🕷 Tracking Issue

No response

[yihuiliao]

Closing because #8820

We recommend using CustomDialog if you need custom widths

[synox]

We cannot use CustomDialog because it does not have support for the layout of Header and Footer, that we need.

When doing the following, it does not lay out the components correctly, since it does not support Heading and Footer. I would have to implement (copy from Dialog.jsx) myself, we defeats the purpose.

<CustomDialog isDismissible={true}>
    <Heading slot="title">Dialog title</Heading>
    <Header>Header</Header>
    <Content>
       hello world
    </Content>
    <Footer><Checkbox>Don't show this again</Checkbox></Footer>
    <ButtonGroup>
        <Button onPress={close} variant="secondary">Cancel</Button>
        <Button onPress={close} variant="accent">Save</Button>
    </ButtonGroup>
</CustomDialog>

@yihuiliao Please consider re-opening.