improve password validation

[FroggyRocky]

improve password validation: min 8 chars in total, min one uppercase, min one lowercase letters and min one number and min one special character. Validation integrated into handleSubmit function.
Additionally, I added styles to errors to be rendered in the next line, in column with input fields, not inline with input fields as the errors might be long this time and it looks not very good if errors are inline with the input fields

[gitfrosh]

@FroggyRocky Thank you for your hard work on this issue! It's much appreciated. However, it looks like a unit test is currently failing. Could you please take a look at it when you have a moment?

[MateuszKikmunter]

Also PR contains only frontend changes, what about backend validation? Then we also need to consider existing users and existing passwords.

[MateuszKikmunter]

Tests are failing for these changes. Can you please take a look at it when you some time @FroggyRocky ? Also would you consider adding backend validation?

[FroggyRocky]

right on! Will do, thanks!

[FroggyRocky]

@MateuszKikmunter and what about existing users? I didn't get the point, since I implemented additional validation only for password in sign-up, not login. I will implement the validation on the backend only for register controller as well. Existing users should be fine, no?

[MateuszKikmunter]

@MateuszKikmunter and what about existing users? I didn't get the point, since I implemented additional validation only for password in sign-up, not login. I will implement the validation on the backend only for register controller as well. Existing users should be fine, no?

Makes sense, I thought that you'll add it for the log in action too but having it only for register is sufficient. Thanks for the PR!