Remove example application causing dependency management headaches

[sdassow]

It happened in the past that the Fyne project had to deal with circular dependency/versioning issues, and when trying to update go-locale to get the latest fixes it happened again, which made me investigate...

Having a Fyne example application as part of go-locale leads to a (circular) dependency chain that is conceptually calling for trouble, and I would like to suggest solving this by removing examples/golocale-gui/ and updating go.{mod,sum} accordingly.

Since go-locale is integrated in Fyne anyways, do we still need this example?

[jeandeaual]

This example was mostly used to show how to use the library with Fyne.
Since, as you pointed out, Fyne now integrates this library directly, I’m fine to have it removed if it helps fix circular dependency issues and reduce the number of dependencies of this project.

I do have one small request: could you please also remove the reference to this example from README.md?

[jeandeaual]

Great, thank you!