add gateway connector capability config

[DavidOrchard]

CAPPL-19

1. toml/types.go add

type ConnectorConfig struct {
type WorkflowConnectorConfig struct {

and add

WorkflowConnector WorkflowConnectorConfig `toml:", omitempty"`

to Capabilities.

2. core/config/capabilities_config.go add

type ConnectorConfig interface {
type ConnectorGatewayConfig interface {
type WorkflowConnectorConfig interface {

3. services/chainlink/config_capabilities.go add

type workflowConnectorConfig struct {

4. delete core/services/gateway/connector/config.go
5. core/services/gateway/connector/connector.go import config update ConnectorConfig to config.ConnectorConfig update function var from config to configLocal Now has a type error on configLocal.donId, see comment.