Add ability to edit person marriages and children

[rafgugi]

Description

Continuing from #1, we want the app to allow editing the relation: add/remove marriages and add/remove children.

Expected behavior

For each row, there will be some buttons to add spouse, add children, or remove the current person.

Additional context

This feature would greatly improve the user experience and make it more efficient to update multiple person data at once.

[rafgugi]

#8 only covers the adding child and spouse. Still, need to add a feature to remove a person