[go_router_builder]: ShellRoute support

[hawkkiller]

This PR adds possibility to generate shell routes from the newest 5.0.0 API.

flutter/flutter#111909

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[hawkkiller]

@chunhtai Hi! It is my first contribution here. Looks like you've reviewed previous PR about go_router.

[hawkkiller]

[hawkkiller]

The go_router change need to go in with a separate pr first, can you open a new one and move the go_router change there?

of course, but how to depend on it, so go_router_builder can see new APIs? Or when the changes approved for go_router, then we publish new library ver and after it we start implementing the go_router_builder stuff? @chunhtai

[chunhtai]

of course, but how to depend on it, so go_router_builder can see new APIs? Or when the changes approved for go_router, then we publish new library ver and after it we start implementing the go_router_builder stuff? @chunhtai

yes, once the go_router change is merged, the go_router_builder should be able to see the change, we will need to bump the go_router version in example folder though

[hawkkiller]

understood, thank you! i will do the changes in go_router and remove them from this PR.

[Skogsfrae]

@hawkkiller any update on this?

[stuartmorgan]

@hawkkiller Are you still planning on updating this PR based on the feedback above?

[hawkkiller]

@stuartmorgan @Skogsfrae check this https://github.com/flutter/packages/pull/2730 but thanks for the reminder :)