Date input without date picker

## Description
The date picker is great for choosing dates ahead or looking for dates you are unsure of. But if your filling in dates you know it is easier to fill it out without the helt of a date picker.

[Guidelines for this component here](https://docs.altinn.studio/app/design/guidelines/components/date/)
This is inspired by the [Gov.uk component](https://design-system.service.gov.uk/components/date-input/)

## Screenshots

## Acceptance criteria
> Describe criteria here (i.e. What is allowed/not allowed (negative tesing), validations, error messages and warnings etc.)

## Specification tasks
- [ ] Design for Altinn Studio
- [ ] Do we need to look into any WCAG issues? (Label and validations)

## Development tasks
> Add tasks here

## Test
> Add test cases here as checkboxes that are being tested as part of the changes.

Start by examining the existing date picker component and the linked Altinn and GOV.UK date-input guidelines. The issue does not name files, tests, acceptance criteria, validation rules, or error messages, so these requirements and any WCAG considerations need to be settled before implementation. Done should include an agreed design, specified behavior, implementation, and tests.

Written by the indexing model from the issue text.