[CCM-11438] Update template guidance

[nicki-nhs]

Description

• Create new ContentRenderer component to render text, list or code sections and add unit tests
• Changes CodeExample to use <pre> to support consistent multi line formatting and add global styling
• Update MarkdownContent component to support simple string content as well as arrays of content and update tests and use cases
• Implement support for ID and test IDs in MarkdownContent component
• Add kebab case util and refactors usage of the previous one
• Refactor MessageFormatting and Personalisation components to be dynamic and driven by the content
• Remove redundant components for message formatting e.g. HorizontalRule
• Rename MessageFormatting prop to templateType
• Update the content to match the new designs
• Add new IDs and aria label content
• Update unit tests and playwright tests
• Fix layout issue on all create template forms and update styling to match prototype
• Refactor the footer on the SMS template form to use the new ContentRenderer component

Screenshot

(others in the ticket)

Context

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming

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Sensitive Information Declaration

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• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.