GDScript 2.0: Rename Tween.set_trans() to Tween.set_transition()

[miv391]

This suggestion concerns Godot 4's Tween.

set_trans is the only Tween method that uses abbreviated method name. Abbreviations are not always bad, but in this case I think there are no good reasons for using abbreviation as "trans" is not a common and well known abbreviation of "transition". It could as well mean "transformation", "transport" or "translate". Slightly longer names are not practical problems as code completion is available. Also, set_transition would not be the longest Tween method name, there are even longer names.

I suggest that set_trans method name is changed to set_transition. Also the TransitionType enums should use the same naming, e.g. Tween.TRANSITION_BOUNCE rather than Tween.TRANS_BOUNCE.