Meta API (/meta): Add the sql_table field to the response

[bhuvansingla]

The /v1/meta API endpoint does not include the sql_table field. Even with the ?extended query param the sql_table field does not exist, even though sql does. It would also be great to have this included unless there is a good reason not to.

I believe it's the following function that needs to be adapted along with the unit tests:

cube/packages/cubejs-api-gateway/src/helpers/transformMetaExtended.ts

Line 37 in e8d81f2

function transformCube(cube: any, cubeDefinitions: any) {

I'm happy to open a pull request for the same!