Add ability to copy a data source and its points

[terrypacker]

Add a REST endpoint and UI functionality to be able to copy a data source (and optionally its points).

/v2/data-sources/copy/{xid}

Note this issue about performance which has been taken into consideration in the design of the endpoint:

MangoAutomation/ma-core-public#681

[terrypacker]

There is a node test in dataSource.spec.js. The only difference in this endpoint to the v1 version is that you can optionally copy the points, the default is to not copy points.

[terrypacker]

@Puckfist @jazdw The existing permissions are such that you only need permission to the existing data source to copy it. I was thinking this should also require the global data source management permission?