APE 5: COPY FROM syntax

We're proposing to change the current syntax for COPY FROM.
The current syntax looks as follows:

COPY Customers
USING localfs (
  ("path"="asterix_nc1://data/nontagged/customerData.json"),
  ("format"="json")
);

This syntax uses the old way of configuring the adapter localfs.

We propose a a new syntax that uses a WITH clause (similar to the syntax that is used for feeds).

Concretely we propose to change the syntax to be as follows:

COPY Customers
FROM localfs
PATH ("asterix_nc1://data/nontagged/customerData.json")
WITH {
  "format": "json"
};

The proposed syntax

1. Introduces the use of FROM <adapterName> and
2. Mandates the use of PATH (instead of having it in the USING parentheses).
   

Additionally, the proposed syntax will make both COPY FROM and COPY TO less different.

Example of COPY TO:

COPY Customers
TO localfs
PATH("localhost:///myData/Customers")
WITH {
  "format" : "json"
};