start TextList with 2 fields instead of 1

[eric-burel]

All in the title:

The tricky part is not really to start with 2 fields, but to handle those fields afterwards.

• Adding an empty item when initializing the "items" state might be a good approach? But what happens when fields are emptied on blur?
• What happens if user starts filling the second field?

[eric-burel]

This PR https://github.com/Devographics/Monorepo/pull/279 alters the value rather than using "virtual" last items. The problem is that it may mess up the value we store and complicates empty inputs deletion.

Instead we should turn lastItem into lastItems or virtualItems. This means:

• be careful with input indices: above "items.length" they are virtual
• be able to have multiple virtual items when there are no "real" items, but only one virtual items when there are "real" items

It complicates the current code too much, a reducer should be involved to have a clearer state here, with operations to make a virtual input real, manage the number or virtual inputs etc.

[eric-burel]

Done, the hook that handle virtual/real items is reusable and could serve controlled or uncontrolled components (it could be used in the CheckboxGroup namely). It would benefit from being rewritten with "useReducer" (should have started there...) but works well.