feat: Update user display name

[apomalyn]

As a user, I want a way to update my name on the application

Requirements

• Update the Profile view to allow the user to modify its name
• Apply changes on the database, Firebase and API

What needs to be done

• Update the Profile view model to:
  • have a TextEditingController with:
  • the default value is the current user display name
  • listener to onEditionComplete that:
    • calls UserRepository.updateSelf
    • update disableDisplayNameTextField to false
    • unfocus the controller
  • have a disableDisplayNameTextField boolean, default = false
  • have an onEditDisplayNameButtonPressed that:
  • update disableDisplayNameTextField to true
  • focus on the controller
  • open the keyboard
• Update the Profile view:
  • change the current display name Text widget with a TextField(readOnly: viewModel.disableDisplayNameTextField, controller: viewModel.controller),
  • viewModel.disableDisplayNameTextField == true strip it to all decoration so it appears like a Text
  • make it appear like a normal TextField with InputDecoration to send completion
  • add an IconButton on the right of the TextField
  • visible only when viewModel.disableDisplayNameTextField == true
  • when pressed, call viewModel.onEditDisplayNameButtonPressed

Dependencies

Child of #130

Depends on:

• 145

• 148