Please add env/envFile launch configuration attibutes

[db4]

It can be done just the same way as in Node.js debugger:

• env - optional environment variables. This attribute expects environment variables as a list of string typed key/value pairs.
• envFile - optional path to a file containing environment variable definitions.

More details are there: https://code.visualstudio.com/docs/nodejs/nodejs-debugging

[hackwaly]

Done. https://github.com/hackwaly/vscode-ocaml/commit/80dd7e278c3d9aa1cba819ad97d19c9672e6926f