[Bug]: graphML file issue regarding fuel nodes

[Timon-R]

The Issue

The graphML file (output of the visualisation function to represent the reference energy system) does not include a fuel description.
This makes it more difficult to work with the file in programs like yEd as the nodes for the fuels don't have any data in regard to their desription.
The fuel description is only added as an ID but not as a readable key, which is different for technologies and emissions.
See output below.

Expected Behavior

The ID of a node can't be displayed using yEd, therefore the desription of a fuel is not available.

Steps To Reproduce

Run the visualisation command and try to use the graphML file in yEd or equivalent software.

Log output

<node id="SEWSSTPH1">
      <data key="d0">technology</data>
      <data key="d1">yellow</data>
      <data key="d2">rectangle</data>
      <data key="d3">filled</data>
      <data key="d4">SEWSSTPH1</data>
    </node>
    <node id="DKBF">
      <data key="d0">fuel</data>
      <data key="d3">filled</data>
      <data key="d2">circle</data>
      <data key="d5">0.1</data>
      <data key="d6">0.1</data>
      <data key="d4" />
    </node>

Operating System

Windows

What version of otoole are you running?

1.1.0

Possible Solution

Add the name of the fuel for key d4 just like for technologies and emissions like this:

fuel
filled
circle
0.1
0.1
DKBF

Anything else?

No response