[ic-date-picker] - move component into core package

[ad9242]

Summary

The ic-date-picker component should be moved from canary into the core package

💬 Description

Work to be done:

• Move component code into the core package (removing from canary)
• Ensure sufficient unit test coverage
• Ensure sufficient cypress testing
• Storybook code\docs may need restructuring to match format in core package

Guidance

The guidance site will need work doing to remove canary status

Additional info

Would need to be done after\alongside #2460

[GCHQ-Developer-741]

https://github.com/mi6/ic-design-system/issues/1156