EpMethodModification has wrong page name for oldMethod when creating extension methods

[chisandrei]

EpMethodModification stores the old and the new methods as RGMethodDefinition. When creating an extension method by moving a method to another package the oldMethod object has as package the name of the new package instead of the name of the initial package containing the method.

Scenarios to reproduce:

• create two package PackageA and PackageB
• create a class TestClass in PackageA
• create a method targetMethod
• move targetMethod from PackageA to PackageA

In this case the EpMethodModification event as PackageB as old package for the method.

Tested in Pharo-11.0.0+build.405.sha.490e0fb59ad4ce97a5faeb044b2d1ebe306cd691 (64 Bit)