Add support for React Server Components (RSC), fix Rollup duplicate 'use client' directives, prepare beta release

[colinrotherham]

This PR adds support for React Server Components (RSC)

Our dot-separated Card, Card.Heading, Card.Description style currently has RSC issues as shown in:

• Multipart Namespace Components: Addressing RSC and Dot Notation Issues

As a workaround, I've exported CardHeading and CardDescription to resolve this, otherwise dynamically assigned child properties become undefined using Next.js App Router:

 ⨯ [Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.] {

I've also swapped rollup-plugin-preserve-directives for rollup-preserve-directives

The current plugin is causing duplicate 'use client' directives to be added:

./node_modules/nhsuk-react-components/dist/esm/components/content-presentation/table/TableSectionContext.js
   ╭─[/path/to/project/node_modules/nhsuk-react-components/dist/esm/components/content-presentation/table/TableSectionContext.js:4:1]
Error:   × The "use client" directive must be placed before other expressions. Move it to the top of the file to resolve this issue.
1 │ "use client";
2 │ import { createContext } from 'react';
3 │ 
4 │ 'use client';
   · ─────────────
5 │ var TableSection;
6 │ (function (TableSection) {
7 │     TableSection[TableSection["NONE"] = 0] = "NONE";

[colinrotherham]

See sample project for a thorough Next.js SSR example:
https://github.com/colinrotherham/nhsuk-react-components-nextjs-app

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.9% Duplication on New Code

See analysis details on SonarQube Cloud