Add Workers Logs Schema

This appears to be the default schema for workers events on BigQuery. Can we get this added (I can PR if desired)

```
[
{
"mode": "REPEATED",
"name": "ScriptTags",
"type": "STRING"
},
{
"mode": "NULLABLE",
"name": "ScriptName",
"type": "STRING"
},
{
"mode": "NULLABLE",
"name": "Outcome",
"type": "STRING"
},
{
"mode": "REPEATED",
"name": "Exceptions",
"type": "STRING"
},
{
"mode": "NULLABLE",
"name": "EventType",
"type": "STRING"
},
{
"mode": "NULLABLE",
"name": "EventTimestampMs",
"type": "INTEGER"
},
{
"mode": "REPEATED",
"name": "Logs",
"type": "STRING"
},
{
"fields": [
{
"fields": [
{
"mode": "NULLABLE",
"name": "Status",
"type": "INTEGER"
}
],
"mode": "NULLABLE",
"name": "Response",
"type": "RECORD"
},
{
"fields": [
{
"mode": "NULLABLE",
"name": "Method",
"type": "STRING"
},
{
"mode": "NULLABLE",
"name": "URL",
"type": "STRING"
}
],
"mode": "NULLABLE",
"name": "Request",
"type": "RECORD"
},
{
"mode": "NULLABLE",
"name": "RayID",
"type": "STRING"
}
],
"mode": "NULLABLE",
"name": "Event",
"type": "RECORD"
}
]
```

No file or test is named. Start by locating the repository's existing BigQuery schema definitions and the entry point that handles worker event schemas, then compare their structure with the supplied JSON. Done means the Workers Logs schema is added in the appropriate location and matches the fields, types, and modes shown.

Written by the indexing model from the issue text.