schemas: Add for `FCMaterials` data

Odyssey Update 12 added a new FCMaterials Journal event and accompanying file. This lists any Fleet Carrier/Bartender orders for buying or selling Odyssey-specific materials (used to upgrade suits and weapons).

There is also data for this in the CAPI /market endpoint.

So, we want a new EDDN schema to allow for relaying data about this.

1. It should use the FCMaterials.json format as its basis.
2. But the README should also document the known CAPI format, and how to mutate it into the Journal/schema format.

Example FCMaterials.json:

{
  "timestamp":"2022-06-08T12:44:19Z",
  "event":"FCMaterials",
  "MarketID":3700710912,
  "CarrierName":"PSI RORSCHACH",
  "CarrierID":"K4X-33F",
  "Items":[
    {
      "id":128961533,
      "Name":"$encryptedmemorychip_name;",
      "Name_Localised":"Encrypted Memory Chip",
      "Price":500,
      "Stock":0,
      "Demand":5
    },
    {
       "id":128961537,
      "Name":"$memorychip_name;",
      "Name_Localised":"Memory Chip",
      "Price":600,
      "Stock":0,
      "Demand":5
    },
    {
      "id":128972290,
      "Name":"$campaignplans_name;",
      "Name_Localised":"Campaign Plans",
      "Price":600,
      "Stock":5,
      "Demand":0
    }
  ]
}

CAPI example (not from the same FC as above):

"onfootmicroresources": {
  "sales": [],
  "purchases":[
    {
      "name":"weaponinventory",
      "locName":"Weapon Inventory",
      "total":30,
      "outstanding":30,
      "price":90000
    },
    {
      "name":"chemicalinventory",
      "locName":"Chemical Inventory",
      "total":30,
      "outstanding":30,
      "price":90000
    },
    {
      "name":"digitaldesigns",
      "locName":"Digital Designs",
      "total":90,
      "outstanding":90,
      "price":120000
    },
    {
      "name":"operationalmanual",
      "locName":"Operational Manual",
      "total":60,
      "outstanding":60,
      "price":70000
    },
    {
      "name":"productionschedule",
      "locName":"Production Schedule",
      "total":60,
      "outstanding":60,
      "price":100000
    },
    {
      "name":"manufacturinginstructions",
      "locName":"Manufacturing Instructions",
      "total":30,
      "outstanding":30,
      "price":90000
    }
  ]
}```
So, it *looks* like the CAPI data 'fulfillment' is inverted, with `outstanding` instead of `Stock` or `Demand`, but this will need confirming.

Also whilst the Journal has the nice separate `CarrierName` and `CarrierID` I'm not sure that's available in the CAPI data.

[Eahlstan]

We also need to be 100% sure that the CAPI data is there generally, and not only for the owner of the FC.

I’d say it is. My bubble commander doesn’t have a carrier and got that data from 3 different carriers (I only tried those 3).

[Athanasius]

The schemas are now live.