Add support for cross_reference items

[clemens-msupply]

Legacy mSupply supports items of type cross_reference.

Cross references refer to alternate names for a certain item, for example, Acetylsalicylic Acid can also be known as Aspirin.

Also see for more information about cross references in mSupply:
https://docs.msupply.org.nz/items:adding_a_new_item?s[]=cross&s[]=reference#cross_reference_items

Describe the solution you'd like 🎁

Below tasks can be broken down into separate issues:

• Sync through cross-reference items
• Display these items for search in frontend
• If a user selects an item from its alias then the normal item should be saved NOT the cross-reference item
• The normal item name should be displayed not any alias it may go under

Describe alternatives you've considered 💭

Moneyworks Jobcode 🧰

[Chris-Petty]

https://github.com/msupply-foundation/msupply/issues/14726

As is being discussed there, the there was a bug resolved in mobile in 2018 where it had been treating cross reference items just like a normal item and some users used them like a normal item.

So the problem is a data issue, fortunately it seems to affect very few records across our users.

So this issue perhaps has two directions:

1. Close, because the data will be resolved on the central server.
2. Be rejigged into really "Supporting" cross reference items, that is to say add the functionality to see cross reference items in item selection lists, and when selected it selects the "referenced" item (e.g. "Panadol" -> "Paracetamol 500mg tablets"). Could be a new issue?

For the rust devs, it's mSupply's equivalent to aliasing a type 😉.

[mark-prins]

@jmbrunskill this may be useful for GAPS? the ability to have a cross-reference item for the Immunisation program

[roxy-dao]

Setting to low priority. But @mark-prins will double check. Maybe to do with item variants?