[objective_c] Implement NSNumber methods for bool

[knopp]

Adds bool.toNSNumber() extension method, NSNumber.isBool check and add converter support for bool.

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[knopp]

Not sure why there are so many changes in generated bindings, is that expected?

[github-actions]

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API leaks ✔️

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Breaking changes ✔️

Package	Change	Current Version	New Version	Needed Version	Looking good?
objective_c	Breaking	9.3.0	9.4.0-wip	9.4.0-wip	✔️

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Changelog Entry ❗

Package	Changed Files
package:objective_c	pkgs/objective_c/lib/src/converter.dart pkgs/objective_c/lib/src/ns_number.dart pkgs/objective_c/lib/src/objective_c_bindings_exported.dart pkgs/objective_c/lib/src/objective_c_bindings_generated.dart

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[liamappelbe]

I think technically renaming NSNumberIsFloat is a breaking change, even though it's unlikely to actually affect any users. But just to be safe, it would be better to add a separate NSNumberIsBool interface.

As for the bindings diffs, no, they're not expected. I suspect you're using a different version of xcode than me and the github bot. Some of the diffs look problematic too. Are you able to update your xcode?