Feat/notification2 support

[reubenmiller]

initial notification2 support

New c8y notification2 command to managed notification2 subscriptions and tokens

Preface

Notification2 needs to be enabled in a tenant before it can be used. In addition you will require the ROLE_NOTIFICATION_2_ADMIN role to access it.
Read the documentation to further understand the new messaging service.

Examples

# create a new subscription (you only need to do this once)
c8y notification2 subscriptions create --name registration --context tenant --apiFilter managedobjects

# list all subscriptions
c8y notification2 subscriptions list

# subscribe (this starts a client using a token automatically)
c8y notification2 subscriptions subscribe --name registration --consumer client01 --duration 10min

# Start listening to a subscription name registration but only include CREATE and UPDATE action types (ignoring DELETE)
c8y notification2 subscriptions subscribe --name registration --actionTypes CREATE --actionTypes UPDATE

# Or subscribe and use the results in other commands
c8y notification2 subscriptions subscribe --name registration --consumer client01 \
| c8y events create --text "New notification" --type "c8y_Notification"