Erase of WID 'nodes' types

If you open a BPMN diagram that has wid info without a wid file, as soon as I save it, the marshaller erase that info, treating as regular nodes

It should be also possible to see a custom task name,input, output without needing the wid file (probably we should display this in read only mode

In case auto-save is enabled, the type is erased permanenty.

Acceptance criteria:

Actual

• When opening a BPMN process without the related WID file:
  • Custom Tasks are converted to None Tasks
  • Custom Task properties are not accessible from Properties Panel
  • On save/auto-save the properties defined for the Custom Task are lost.

Expected

• When opening a BPMN process without the related WID file:
  • Custom Tasks shall remain as Custom Tasks
  • Custom Task Properties shall be accessible from Properties Panel
  • On save/auto-save(VSCode) the properties defined for the Custom Task shall be preserved even if edited.
  • Custom Tasks shall be presented with the default icon
  • It shall be possible to cut/copy and paste Custom tasks
  • Only the Milestone Custom Task shall be available from the Pallete

• The process is reopened with the proper WID file and the icon files exist:
  • the correspondent icons shall be displayed in on the Custom Tasks
  • In addition to Milestone all the Custom Tasks defined in the WID file shall be available from the Pallete
  • Custom Task Properties shall be accessible from Properties Panel
  • On save/auto-save the properties defined for the Custom Task shall be preserved even if edited.