Update Go binding for FDC3 3.0 additions

## Enhancement Request

FDC3 3.0 removes previously deprecated functions from teh API and adds several new functions to the Desktop Agent, Channel and IntentResolution APIs and updates others, such as:
- Metadata parameters to `fdc3.broadcast()`, `channel.broadcast()`,`fdc3.raiseIntent()`, `fdc3.raiseIntentForContext()`, `ContextHandler`, `IntentHandler` and the associated `ContextMetadata` and `AppProvidableContextMetadata` types
- `fdc3.close()`,
- `fdc3.addIntentwithContextListener()`,
- `fdc3.addContextListener()` (with an array argument for context type),
- `IntentResolution.getResultMetadata`,
- `Channel.getCurrentContextWIthMetadata`
- etc.

Update the FDC3 Go binding to reflect these changes.