Restructure "previous iteration" values as simply inputs to the plasma

[andrewfullard]

Right now they are part of the plasma as special objects.

[karthik11135]

@andrewfullard
I was thinking of calculating the previous iteration values in the factory class and then pass as inputs (previous iteration properties array) to the base plasma. Can I do this?

Edit : I worked on this issue, I passed previous iteration properties array and prev output dict to baseplasma. However I'm still including prev iteration properties in the plasma modules.
If this is okay, I'll raise the PR. If not, I'm happy to make necessary changes.

[karthik11135]

Hi @andrewfullard,
This is just a follow up message. Kindly take a look at this approach when you are free.

Thanks.