Fix curve edit `set_point_position`

[aryan-11825114]

Fixes #95752

Before

before.webm

After

after.webm

[aryan-11825114]

Hey there, I was just wondering if this could be merged sooner, it would mean the world for a newbie contributor like me 😀

[adamscott]

cc. @Geometror

[passivestar]

Didn't find this PR before opening my PR, but this PR breaks the curve if the point ends up at a different index after being dragged and also when you try to undo such change (If you want to fix it I'll close my PR)

[aryan-11825114]

Didn't find this PR before opening my PR, but this PR breaks the curve if the point ends up at a different index after being dragged and also when you try to undo such change (If you want to fix it I'll close my PR)

Yes, thank you, I have rebased and modified the P.R., it is now identical to yours

[kleonc]

Regarding PR/commit title "Fix" would be better than "fixing":

~fixing~Fix changed signal emission in Curve::set_point_offset

Haven't thought you'd use my suggestion from https://github.com/godotengine/godot/pull/96296#discussion_r1986979848 as is. :upside_down_face:

[aryan-11825114]

ht you'd use my suggestion from #96296 (comment) as is. 🙃

Sorry not a creative person myself, also english is my second language 😅

[Repiteo]

Thanks!

[akien-mga]

Cherry-picked for 4.4.1.