feat: add magic flag to xml template

[bshaffer]

We added support for magic methods added to the Class template recently, but in the generated structure.xml, there's no way to tell if they've been inherited, or if they're magic methods.

Summary of changes:

• sets inherited_from for magic methods
  • This logic is determined in the template when method.class does not match class. This may not be the best way, but it seemed like the approach with the least churn
  • this feature is (I think) important, since it exists for other methods, and so the behavior was inconsistent
• a magic="true" attribute to the <method> tag (e.g. <method /* ... */ magic="true">)
  • I think it makes sense to have some way to know if the methods are magic or not, but since the users could check the existence of the @method tag, that's already possible, so I'm 100% okay getting rid of this.

I'd love some feedback here!!

Note: magic is probably the wrong label to use for methods added with __call, because according to the PHP Documentation, PHP magic methods are methods prefixed with __. The methods added with __call are referred to as "overloaded methods", which I also don't like, as that represents something different in other OO languages such as Java.

[jaapio]

I think magic makes sense... as the methods do not exist... but are called in a magic way :-)

I have no better name for them.