fix confluence links to open in new tab, improve rendering

[martindstone]

Background

Confluence pages containing links need to have their links modified so that they open in a new tab

This PR

modifies links found in the retrieved HTML so that they open in a new tab

Checklists

Security

• Security impact of change has been considered
• Code follows company security practices and guidelines

[Copilot]

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

plugins/confluence-plugin/src/components/PageContent.tsx:197

• Directly mutating the 'contents' object may lead to unexpected rendering issues. Consider updating the state using a setter to ensure proper re-rendering.

contents[`${entityPage.id}`].body = fixHtml(contents[`${entityPage.id}`].body, baseConfluenceUrl);