Allow Setting the Port of externalServer to a String

[aarisr]

I have a file:
.vscode/settings.json
with the following content:

{
  "solargraph.externalServer": {
    "host": "localhost",
    "port": "${env:SOLARGRAPH_PORT}"
  },
  "solargraph.transport": "external",
}

I'd like to be able to set the Port from an ENV Variable, currently only String values can be created from ENV Variables.
But if I provide a String in the Settings the Code breaks with:

Failed to start Solargraph: RangeError [ERR_SOCKET_BAD_PORT]: Port should be >= 0 and < 65536. Received ${env:SOLARGRAPH_PORT}.

Could the value of "port" be casted to an integer so that this is possible?

[aarisr]

I think there is a Problem still because the package.json#L65 enforces the port setting to be of type integer