Add Support for Per Actor Type Configuration

## Describe the proposal
The Dapr Runtime added support for per actor type configurations in 1.7. This support needs to be added to the SDKs.

The new configuration looks like:

```json
{
"entities":["actorType1", "actorType2"],
"actorIdleTimeout": "1h",
"actorScanInterval": "30s",
"drainOngoingCallTimeout": "30s",
"drainRebalancedActors": true,
"reentrancy": {
"enabled": true,
"maxStackDepth": 32
},
"entitiesConfig": [
{
"entities": ["actorType1"],
"actorIdleTimeout": "1m",
"drainOngoingCallTimeout": "10s",
"reentrancy": {
"enabled": false
}
}
]
}
```

Implementation can be varied per SDK but should output to the above JSON.

Docs: https://github.com/dapr/docs/pull/2334
Runtime: https://github.com/dapr/dapr/pull/4201

Start by reading the linked Dapr docs PR 2334 and runtime PR 4201 to understand the per-actor-type configuration contract. Then inspect the Go SDK's existing actor configuration entry points and related tests, if present. Done means the SDK supports the configuration and produces JSON matching the documented entitiesConfig structure.

Written by the indexing model from the issue text.