feat: login and registration including error management and tests

[sshanzel]

Changes

Describe what this PR does

• Check whether email exists before proceeding to go for registration
• Login error management
• Registration error management

Events

Did you introduce any new tracking events? Don't forget to update the Analytics Taxonomy sheet

Log the new/changed events below:

Type	event_name	value
Change/New	event name	extra: { ... }

Please make sure existing components are not breaking/affected by this PR

Manual Testing

On those affected packages:

• [ ] Have you done sanity checks in the webapp?
• [ ] Have you done sanity checks in the extension?
• [ ] Does this not break anything in companion?

Did you test the modified components media queries?

• [ ] MobileL (420px)
• [ ] Tablet (656px)
• [ ] Laptop (1020px)

Did you test on actual mobile devices?

• [ ] iOS (Chrome and Safari)
• [ ] Android

WT-187 #done

[sshanzel]

@rebelchris would love to know what you think about this PR including its test cases if you think it does cover what we need to have.

[sshanzel]

Since I will be working on the refactor of reset password flow in a separate PR. I'll be merging this now, and just create another PR to hook up what Viktor has prepared for calling email existence on registration flow.