Add notification banner component

[robkerrybjss]

No description provided.

[robkerrybjss]

Fixes #283

[colinrotherham]

Love seeing this PR opened!

I've added a few comments but nothing huge. We need to carefully review the design system guidance and add a few missing things.

Verifying all the NHS.UK frontend examples work would be really useful too

Think it's only the task list component missing after this 😎

[robkerrybjss]

Thanks @colinrotherham, I've learned a lot by doing this! Really appreciate you taking the time to give this a thorough review.

[robkerrybjss]

Forgot to say on Friday, all the changes you've asked for are in now!

[colinrotherham]

Thanks @robkerrybjss, I'm going to have a look at this now 🙌

I've had to adjust childIsOfComponentType() slightly for React Server Components (RSC) in #285 (see commit) but I'll check everything still works here in your PR too

[colinrotherham]

Thanks for spotting this!

[colinrotherham]

Excellent work here!

I'm just going to rebase onto #285 so we can get it into the next beta

I'm going to fix a few problems I've caused, bear with

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[colinrotherham]

Thanks @robkerrybjss

Will merge this into #285 and get another beta released