Remove sideeffect when opening modal dialog

[vbakke]

In Circular Heatmap, opening the modal dialog displaying the Activity Details, will affect this.YamlObject, and thus affect the export of generated.yaml, with an extra navigationExtras for all activities that have been opened.

The fix was to assign a shallow copy of the activity, before adding the navigationExtras.

[vbakke]

Any comments on this @0x41head? Are you able to reproduce the issue?

1. Open https://dsomm.owasp.org/circular-heatmap in incognito mode
2. Export YAML (Download edited YAML file)
3. Open the modal activity description for Defined build process
4. Export YAML (Download edited YAML file) again
5. Do a diff between the two yaml files, or search for 'navigationExtras'

[0x41head]

I apologize for the delay in getting back to you.
I managed to replicate the issue, and your PR resolves it flawlessly!