enkvadrat

this isn't something they can fix since it is a modded issue.  You could maybe fix it by looking into the world folder. Possibly replacing the end and the nether could fix it.

The same  argument could be said for the end portal frame, still I don’t see any trace of it in the building block tab. 

I don't get why they changed it, 

I think there is not reason to fix this. You wouldn't even have a spawner in survival anyway. The only players that would have obtained a spawner in survival would just get more upset, their ability tp place pig spawners already broke. 

you probably forgot to add the datapack

Press Fn and then F3

melons can't grow onto stone, replace it with dirt

you probably are in adventure mode

pumkins can't grow onto stones try replacing it with dirt

I think the blocks should drop as if mined by a player instead of being deleted