Linter rule suggestion - Nested resource uses the same API version as the parent

We could potentially lint for situations like the following:

```bicep
resource storageAccount 'Microsoft.Storage/storageAccounts@2021-02-01' = {
// ...

resource blobService 'blobServices@2021-02-01' = {
name: 'default'

resource container 'containers@2021-02-01' = {
name: 'my-container'
}
}
}
```

In this example, the `blobServices` and `containers` resources doesn't need to declare an API version - if they doesn't, the API version is inherited from the parent resource.

I think it shouldn't be a linter warning to explicitly override the API version of the parent resource, though - there might be some edge case scenarios where the parent resource must be deployed using one API version and a child must be deployed using a different API version.

Use the nested-resource example in the issue as the starting case and review how the project's linter rules and diagnostics are tested. Confirm the behavior for inherited same-version API declarations versus explicitly different child versions; done means the intended warning boundary is covered by tests.

Written by the indexing model from the issue text.