fix: Fix namespace conflict with new Flutter class Split

[luanpotter]

Description

Fix namespace conflict with new Flutter class Split.

Newer versions of Flutter seem to have introduced a Split class within animation curves which causes a compilation issue within Flame:

The name 'Split' is defined in the libraries 'package:devtools_app_shared/src/ui/split.dart (via package:devtools_app_shared/ui.dart)' and 'package:flutter/src/animation/curves.dart'.
Try using 'as prefix' for one of the import directives, or hiding the name from all but one of the imports.

Checklist

• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• Yes, this PR is a breaking change.
• No, this PR is not a breaking change.

[spydon]

You don't have to worry about this, it has been renamed to SplitPane (it's for the devtools), we're just awaiting the release

[luanpotter]

Sg, closing this then. It breaks with master that is need for 3d stuff.

[spydon]

Sg, closing this then. It breaks with master that is need for 3d stuff.

We could merge this meanwhile if you want, it doesn't hurt