feat: create postcode lookup component in Component Library

[michael-odonovan]

PR description

What is it doing?

Creates new postcode lookup component in our Component Library that can be used in forms that need a postcode lookup.

Why is this required?

DRY, building up on Component Library.

link to Jira ticket:

https://comicrelief.atlassian.net/browse/ENG-2665

Quick Checklist:

• My PR title follows the Conventional Commit spec.

• I have filled out the PR description as per the template above.

• I have added tests to cover new or changed behaviour.

• I have updated any relevant documentation.

Important! - lastly, make sure to squash merge...

[AndyEPhipps]

Looking good, man! If we could just stop this button from drifting into the void on larger screens, I think we'll be good:

Just want to zoom out for a second though; are we thinking about this existing as a 'drop-in' to be used to populate already existing address fields within the parent form itself.. rather than it working like the Storybook equivalent?

[michael-odonovan]

@AndyEPhipps Not sure what you mean about the drop in usage, I think the existing storybook one is dropped into the current contact-us repo:
https://github.com/comicrelief/contact-us/blob/master/src/components/Giro/Giro.js
This would be used similarly. Probably not understanding what you are getting at sorry.

[AndyEPhipps]

@AndyEPhipps Not sure what you mean about the drop in usage, I think the existing storybook one is dropped into the current contact-us repo: https://github.com/comicrelief/contact-us/blob/master/src/components/Giro/Giro.js This would be used similarly. Probably not understanding what you are getting at sorry.

So I really meant the fact that this Lookup component doesn't include any address fields itself; it just uses the Lookup API, then spits out a string made up of each part of the address.

How would you integrate this component within a real form?

[AndyEPhipps]

Aw jeez, dude, I feel like I wasn't being clear enough; I was really just asking a legit question as to what was the plan of action, it wasn't a rhetorical one implying "we should have address fields".

That said, this all looks nice, if we could just have functional parity with the OG one here; ('enter manually' button, show/hiding the fields, props to set button and error copy), we'll be onto a winner.