[A11Y][PIN code] Improve PIN code focus management

Prerequisites

• I have searched the backlog for duplicate or closed feature requests

Your test device

Samsung and iOS

OS Version

.

App version

1.2.0

Describe the issue

• when focus moves to the next field, the new focused input is not vocalized: this field shall be vocalized to inform the user
• when user deletes an input, the focus goes back to the previous field: the focus should stay in the deleted input
• the current input name is "code à chiffres 1, code à chiffre 2...", so if we fill in a digit we hear for example "code à chiffres 1, 5", so it can be confusing bewteen the position and the value: we should rename the fields like "1er chiffre, 2eme chiffre..." / "1st digit, 2nd digit...."
• inputs are grouped with a global name "entrez votre code à 6 chiffres, double tap pour modifier" but the double-tap doesnt work : allow double-tap to edit the first digit

Expected Behavior

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