RUMM-2266 Enable Session Replay models generation

[ncreated]

What and why?

📦 This PR fixes 2 problems discovered when running models generation for Session Replay schemas. With this fix, the generator makes successful run on session-replay-mobile-events-format.json and prints Swift code.

This PR doesn't yet:

• Decorate SR models code appropriately. Similar to RUM, there are several things we may want to adjust in produced code (e.g. naming, or reusing common types) to make it more convenient to work with.
• Restructure rum-models-generator package to include separate generation tracks for RUM and SR.

Both elements will be delivered in next PRs.

How?

First, I enhanced JSON schema reader with inferring type if it is not explicitly defined. This is the case of mutation-data-schema.json which defines following array items without declaring type: object:

"items": {
   "required": [
       "wireframe"
   ],
   "properties": {
       "previousId": {
           "type": "integer",
           "description": "The previous wireframe id next or after which this new wireframe is drawn or attached to, respectively.",
           "readOnly": true
       },
       "wireframe": {
           "$ref": "wireframe-schema.json",
           "description": "The new wireframe that needs to be added to the screen.",
           "readOnly": true
       }
   }
}

In such case ☝️, we can infer that item is of type: object, because it defines properties.

Alternatively, we could consider updating mutation-data-schema.json with type information. I don't do it for two reasons:

• couldn't find anywhere in JSON schema doc if type is a mandatory field (seems not);
• other generators (Kotlin + TS) seem to handle this case, so it sounds reasonable to include it in ours.

Second, there was one generation branch in oneOf resolution marked as "not yet supported". In this PR I'm adding support to mixing JSONObject and JSONOneOf definitions in a single oneOf.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference
• Add CHANGELOG entry for user facing changes

Custom CI job configuration (optional)

• Run unit tests
• Run integration tests
• Run smoke tests

[maxep]

👌