Improve pop up window when adding a sector

[camiplata]

What is the purpose of having the UNION option set as default with adding a new sector on the assembly view? Both the text of the pop-up window and the CTA makes reference to UNION.

I would like to recommend having all options with the same desing and to display only the text once the option has been selected, and that such a text to be specific to the option selected.

[mdoering]

If you attach a sector is never makes sense if the target rank equals the subject rank, hence the default changes from attach to union. With merge sectors there is now another option than union. But I would expect people to manage merge sectors rather through the sector view than the assembly tree

[camiplata]

The project tutorial guides the user to use attach, and even if the default changes to union as a user one can still click on attach.
Then we may need to make several additional changes on the tutorial and on the UX.

Regarding the merge, using it in the assembly is explained on the tutorial wich I think is fine. It really depends on each project needs, if is better to add it from the assembly or from the sectors tabs. On the other hand, If merging in the assembly renders a bad behavior then it shouldn´t be an option all.