Give back int circuits when loading legacy save

[Tictim]

What

This PR makes int circuits to be moved to one of the vacant machine slots when updating the mod.

Implementation Details

The Ghost Circuit PR (#1458) made circuits to disappear when updating. This can be prevented by moving the circuit item to machine input slot during NBT deserialization. If there's no space left in the machine, the circuit will be set as ghost circuit and the item itself will be voided, like in aforementioned PR.

Although not necessary, numerous implementation details related to ghost circuit was changed, namely the change of ghost circuit inventories to just store one integer value for save/load.

Outcome

Give back int circuits when loading legacy save.

Additional Information

This PR needs to be released along with #1458, otherwise this PR will break.

Potential Compatibility Issues

This PR renames FakeCircuitSlotWidget to GhostCircuitSlotWidget for unifying term for ghost circuits, which is technically an API-breaking change.

[Caedis]

Looks good from me.

Things I tested:

• Mold in circuit slot before -> Mold in open input slot after (most possible void scenario due to fluid solidifier having only 1 item slot and some people using the ic slot as storage)
• Shift right clicking machine with IC changes ghost circuit value to real IC value
• Left clicking ghost IC slot with real IC changes value to match
• Scrolling in ghost circuit slot works as expected
• Left clicking empty IC slot causes ghost IC to appear at config 0
• Right clicking IC slot cause ghost IC to disappear