Use allOf for embedded types

Hello,

I have these types:

```go
package signals

type Addressable struct {
Address int `yaml:"address"`
}

type Unitable struct {
UnitOfMeasurement string `yaml:"uom"`
}
```

```go
package A

type EntryA struct {
signals.Addressable
signals.Unitable
Name string `yaml:"name"`
}
```

And I would like to generate a schema for `EntryA`. I would prefer this schema to look like this:

```json
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://dev.azure.com/Allseas/Innovations/_git/CAM_scl-code-gen.git/schemas/A/entry-a",
"$ref": "#/$defs/EntryA",
"$defs": {
"Addressable": {
"properties": {
"address": {
"type": "integer"
}
},
"required": [
"address"
]
},
"Unitable": {
"properties": {
"uom": {
"type": "string"
}
},
"required": [
"uom"
]
},
"EntryA": {
"allOf": [
{
"$ref": "#/$defs/Addressable"
},
{
"$ref": "#/$defs/Unitable"
},
{
"properties": {
"name": {
"type": "string"
}
},
"type": "object",
"additionalProperties": false,
"required": [
"name"
]
}
]
}
}
}
```

Currently, the schemas are merged and not reused:

```json
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://dev.azure.com/Allseas/Innovations/_git/CAM_scl-code-gen.git/schemas/A/entry-a",
"$ref": "#/$defs/EntryA",
"$defs": {
"EntryA": {
"properties": {
"address": {
"type": "integer"
},
"uom": {
"type": "string"
},
"name": {
"type": "string"
}
},
"additionalProperties": false,
"type": "object",
"required": [
"address",
"uom",
"name"
]
}
}
}
```

Start by tracing how the generator handles embedded Go types and assembles the schema shown for EntryA. Compare the current merged output with the requested allOf structure, including reusable Addressable and Unitable definitions. Done means embedded types are represented through allOf references without losing the fields and required properties of EntryA.

Written by the indexing model from the issue text.