Better syntax errors

[timothee-haudebourg]

Currently using serde to deserialize abstract layouts gives awful error messages when the layout definition is wrong. This PR uses the json_syntax::TryFromJsonSyntax trait that passes code mapping info to the deserializer to provide better syntax error messages.

Some examples of common errors, and the new message provided:

• Missing required property:

error: Layout syntax error
  ┌─ layouts/examples/simple_record.json:6:9
  │  
6 │           "id": {
  │ ╭───────────────^
7 │ │             "intro": []
8 │ │         },
  │ ╰─────────^ missing required entry `value`

• Invalid layout type:

error: Layout syntax error
  ┌─ layouts/examples/simple_record.json:3:10
  │
3 │     "type": "wrong",
  │             ^^^^^^^ invalid type value
  │
  = possible values are `id`, `unit`, `boolean`, `number`, `bytes`, `string`, `record`, `sum`, `list`, `set`, `tuple`, `union` and `intersection`
  = found type `wrong`

• Duplicate entry:

error: Layout syntax error
  ┌─ layouts/examples/simple_record.json:3:2
  │
3 │     "type": "record",
  │     ^^^^^^ duplicate entry `type`
4 │     "type": "sum",
  │     ------ also defined here

• Unexpected entry:

error: Layout syntax error
   ┌─ layouts/examples/simple_record.json:18:2
   │
18 │     "foo": "bar"
   │     ^^^^^ unexpected entry `foo`