Fix component width null

[ERnsTL]

• seems to happen after a few edit cycles;
• Problem:

[TRACE] (client-handler ) tungstenite::protocol: [/home/ernst/.cargo/registry/src/github.com-1ecc6299db9ec823/tungstenite-0.17.3/src/protocol/mod.rs:311] Received message {"protocol":"graph","command":"changenode","payload":{"id":"LibComponent_zw7cy","metadata":{"x":72,"y":216,"width":null,"height":72,"label":"LibComponent"},"graph":"main_graph","secret":""}}
[INFO ] (client-handler ) got a text|binary message
thread 'client-handler' panicked at 'failed to decode JSON message: Error("invalid type: null, expected u32", line: 1, column: 119)', flowd-rs/src/main.rs:194:22
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

• the property "width" is really null

[ERnsTL]

• Problem was that we did not copy over the width and height into the internal datastructures on change_node
• But what remains: noflo-ui does not send width and height on the addnode message, so if we do not move the component (triggering a changenode) then it remains with width: null, height: null which is not good. Wrong behavior on noflo-ui side.

[ERnsTL]

To reproduce:

• connect to the runtime
• add a component, wire it up
• noflo-ui sends addnode message without the width and height in metadata.
• reload noflo-ui
• it reconnects to the runtime
• runtime retuns the width:null and height:null values.

Looks like this after addnode:

Looks like this after reload:

[ERnsTL]

• bug noflo-ui side, reporting bug

[ERnsTL]

• changenode: fix for taking over the width and height is done
• addnode: noflo-ui does not send width and height -> not fixable from here

-> issue noflo-ui side remains