Make the default zoom of the workflow visualizer smaller

[Devessier]

When the visualizer appears, the default zoom is too big. The default zoom should be the same as shown in the Figma document.

[Devessier]

I dived into the topic of controlling the viewport of the workflow diagram canvas. I listed a few things that will need to be discussed later:

• The Figma document mentions that the viewport of the canvas should change when a node is selected. It doesn't seem evident to me what pattern we want to apply to the canvas; it appears that the canvas moves a bit when a node is selected so that it's nearer the center of the viewport, but I can't extract a general rule that can be applied every time.
• It's possible to go to the previous/next workflow by using buttons in the header of workflows' show page. How should the zoom be handled when switching to another workflow?
• How should we handle workflows with many nodes? If we try to fit the whole workflow in the viewport, the zoom will be really small.

Will have to discuss these behaviors with @Bonapara

[Devessier]

According to our discussion with @Bonapara:

• We always want to use the same zoom to fit the diagram in the view; 1.3 can be a good value.
• We want to display the first step of the workflow at top: 20%, as shown in the screenshots below. (1st and 2nd screens)
• When selecting a node, we open the right drawer. This moves the diagram to the left and centers it according to the width remaining visible to the workflow visualizer. We should position the selected node as the previous node is visible enough to be clicked. (3rd screen)

[Devessier]

Check that discussion about setting the default position of the flow: https://github.com/xyflow/xyflow/discussions/3228

[Devessier]

We'll set a default zoom for now and we'll continue working on that task later.