Upgrade to Flutter 3.35

[hjiangsu]

Pull Request Description

This PR upgrades our dependencies and workflows to be compatible with Flutter 3.35.

As part of the upgrade, I migrated over some code from the swipeable_page_route package into Thunder. This was done for a couple of reasons:

• The swipeable_page_route package has widgets that Thunder doesn't use. Those additional widgets are currently incompatible with Flutter 3.35 and would block us from upgrading to 3.35 (until the package is updated).
• Since Thunder only requires SwipeablePageRoute from the package, integrating that logic directly into Thunder will allow us to reduce our external dependencies.

I've also added the swipeable_page_route license into our existing license, similar to some other packages that were migrated to Thunder in the past (e.g., marquee_widget and conditional_parent_widget).

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

Checklist

• If a new package was added, did you ensure it uses an appropriate license and is actively maintained?
• Did you use localized strings (and added appropriate descriptions) where applicable?
• Did you add semanticLabels where applicable for accessibility?