Unable to specify gsp_id through `config.yaml`

[siddharth7113]

Currently there is no way to specify which id samples to make based on gsp_id in configand requires directly using the function PVNetUKRegionalDataset .

Context

It would be great to have an option to make samples for specific gsp_id such as when training the PVnet model for a specific region or just nation i.e gsp_id = 0