Implement "Sign In" page

[alex-anakin]

Overview

Implement page for logging in the application.

Action Items

• The "Sign in" button is disabled by default.
• Enable the "Sign in" button when the input value is not empty (consider spaces as empty input).
• After clicking the "Sign in" button validate inputted symbols in the client using a regular expression.
• If the inputted value is not valid email then show an error.
• If the inputted value is valid check out if it is registered in the VRMS system by sending a request to the back-end.
• If the inputted email is registered then redirect to the temporary dummy page.
• If the inputted email is not registered then show an error. The error should contain a link to the "Create account" page from Implement "Create account" page #322 (or dummy page if it is not implemented).
• Cover implemented component and functionality with tests.

Resources/Instructions

The feature description in the MVP doc.

[OlgaBilogurova]

Done.
Next step - cover implemented LoginContainer functionality with unit tests (mock data, test logic).