feat(core-manager): implement watcher.getEvents action

[sebastijankuzner]

Summary

This PR add new action which is used for querying related data from the watcher database.

Action

Name: watcher.getEvents

Params:

Name	Type	Description
query	Object	Query.

Query:

Name	Type	Description
limit	Number	Query limit.
offset	Number	Query offset.
event	String	Name of event.

Response:

Name	Type	Description
total	Number	Total number of items matching the given query (without limit and offset).
limit	Number	Query limit.
offset	Number	Query offset.
data	Array	Array of watcher data items.

Checklist

• Tests (if necessary)
• Ready to be merged