feat: add Lit renderer directives for dialog

[vursen]

Description

This PR implements a Lit renderer directive for each renderer property of the dialog component in order to provide a better DX for Lit users.

Part of #266

Dialog Content Renderer

import { dialogRenderer } from '@vaadin/dialog/lit.js';

<vaadin-dialog 
- .renderer=${(root, dialog) => render(html`...`, root, { eventContext: this })}
+  ${dialogRenderer((dialog) => html`...`)}
></vaadin-dialog>

Dialog Header Renderer

import { dialogHeaderRenderer } from '@vaadin/dialog/lit.js';

<vaadin-dialog 
- .headerRenderer=${(root, dialog) => render(html`...`, root, { eventContext: this })}
+  ${dialogHeaderRenderer((dialog) => html`...`)}
></vaadin-dialog>

Dialog Footer Renderer

import { dialogFooterRenderer } from '@vaadin/dialog/lit.js';

<vaadin-dialog 
- .footerRenderer=${(root, dialog) => render(html`...`, root, { eventContext: this })}
+  ${dialogFooterRenderer((dialog) => html`...`)}
></vaadin-dialog>

Type of change

• Feature

Checklist

• I have read the contribution guide: https://vaadin.com/docs-beta/latest/guide/contributing/overview/
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
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No Coverage information
0.0% Duplication

[vaadin-bot]

This ticket/PR has been released with Vaadin 23.1.0.beta1 and is also targeting the upcoming stable 23.1.0 version.