api: get_streams (#886)

## Link to GitHub Issue or related Pull Request, if one exists
#0

## Description of change
MSE method of streaming video needs the dimensions up front. This new
api delivers that. Also provides an easier way to determine which
screens are available and a way to discover port number.

## Testing
See pending changes in substream project

src/spice2x/api/resources/python/spiceapi/__init__.py

@@ -2,6 +2,7 @@ from .connection import Connection
 from .request import Request
 from .analogs import *
 from .buttons import *
+from .capture import *
 from .card import *
 from .coin import *
 from .control import *