How to merge strings in Notepad?

Question

Macros

I have an array of data, for example:
milk 1
cow 2
plant 3
milk 4
cow 5
plant 6
milk 7
cow 8
plant 9
Milk, cow and plant always go in this order, you need to combine the lines like this:
milk 1 cow 2 plant 3
milk 4 cow 5 plant 6
milk 7 cow 8 plant 9
And we also need to swap cow and plant:
milk 1 plant 3 cow 2
milk 4 plant 6 cow 5
milk 7 plant 9 cow 8