Wrap: Allow annotations parameter to accept specific fields

[daniel-j-h]

The annotations parameter changed form a bool to specific annotation types.
We need to wrap this in node-osrm, too.

Upstream:

• Issue Allow annotations parameter to accept specific fields osrm-backend#3563
• Pull Request Refactor annotations parameter to accept explicit values osrm-backend#3628

Tasks

• node_osrm.cpp adapt comments
• node_osrm_support.hpp parse from Javascript-land
• adapt docs/api.md

Here's the entry point where we throw an exception currently.

cc @karenzshea

[karenzshea]

I'll hit this after the speed param has also been added as an annotations option.

[daniel-j-h]

In order to not break the ABI here's what we have to do:

• support the old boolean parameter
• allow new string parameters

This is Javascript-land, we can do this by means of checking v8::Value::IsBoolean (old behavior) and v8::Value::IsString() (new behavior).

[chaupow]

How should the API look like?
currently I was thinking of supporting following params:

var options = {
    annotations: 'true'
};

var options = {
    annotations: true
};

var options = {
    annotations: ['distance', 'weight', 'node']
};

does this make sense?

@karenzshea @TheMarex @daniel-j-h @freenerd

[TheMarex]

@chaupow I would suggest not allowing string values but only boolean and array of strings to keep the API surface small.

[chaupow]

So shall we accept bool or an array of string?

Then, I will accept

var options = {
    annotations: true
};
var options = {
    annotations: ['distance', 'weight', 'node']
};
var options = {
    annotations: ['distance']
};

I will not accept

var options = {
    annotations: 'distance'
};
var options = {
    annotations: [true]
};

?

@karenzshea @TheMarex

[TheMarex]

@chaupow exactly.

[chaupow]

merged #299