refactor: Use variable name on toString in component_test.dart

[luanpotter]

Description

This is a cleanup identified on this issue: #2308
Using an amazing unused-code tooling
Now, since Flame is a public API, unused code might not be trivial - it might just mean untested code.

In this case, the unused code is in the tests, which likely means it is indeed necessary.
I tried to infer the intent of the author here, and even considered adding the names of the components to the events, but the events are already always per component, so that was meaningless. I also thought it might be a missing toString, that they would wish to show the component name for debugging purposes, but I didn't see any asserts/logs on the component objects themselves (just the events).
So I concluded there is no reason to keep this field, but lmk if anyone disagrees and I can bring it back and add some function to it.

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.

[st-pasha]

The name field was for debugging purposes: if some test breaks, you can set up a breakpoint and see clearly which component is which. Perhaps a toString() method would be helpful here?

[luanpotter]

Updated!