Update register flow to allow types of users

[nazrinharris]

It could either be a second step, or directly within the screen. A second step would probably be better.

The deed

• [x] Implement RegisterScreenSecond
• [x] Implement chooseUserType() in repository and remote
• [x] Connect said methods with the bloc and react accordingly

I feel like RegisterScreenSecond should be named ChooseUserTypeScreen, as it sounds more descriptive and modular.

• [x] Change name and structure as an independent screen
• [x] Create a new cubit rather than depending on RegisterScreenBloc

[nazrinharris]

Note: It's possible for farmers to have retail stores and businesses to have farms, so make sure those two are rather generic

[nazrinharris]

Should be completed with 48333a7