More changes for generating gstreamer bindings

[RSWilli]

I got some closure name collisions for the generated Connect callbacks. The collisions only happened on action signals which are only to be emitted AFAIK (please verify).

I also needed to preprocess enum member names so I added a set name.

[RSWilli]

There seems to be a diff now. I checked the docs for the GSignalFlags:

G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive objects from user code via g_signal_emit() and friends, without the need of being embedded into extra code that performs pre or post emission adjustments on the object. They can also be thought of as object methods which can be called generically by third-party code.

I don't think that is is necessary to generate methods for those. The diff in the actions pipeline confirms that IMHO. Type safe emit calls would be very nice though.

[RSWilli]

The borrowing creates code like this: https://github.com/go-gst/go-gst/blob/generated_bindings/pkg/gst/gst.go#L35155

or search for "borrow" in the generated packages.

[diamondburned]

FYI I'm likely not going to accept this PR as-is. This diff is a good study for me to add additional APIs into the GIR generator that would permit this for external generators, but adding edge cases from external generators into gotk4 directly is not sustainable in the long term.

[diamondburned]

Please keep this diff around so I can go back and reference it, but I would strongly recommend moving this to a draft PR so that it doesn't block this PR from being merged.

[RSWilli]

I'm completely on your side. I'd like to move the cases for the special types into the go-gst repo, and add some functionality to this PR that allows me to hook into this function.

I'm not quite sure how to do this though, because this is fairly deep into the call stack and quite far from the genmain.Data. If you have a suggestion please let me know.