fix: remove backup, add prettier

[LyubovSugak]

What does this change?

Removes extensive backup
adds prettier
adds extensions (moved from tealium)

Why?

Link to supporting ticket or Screenshots (if applicable)

https://axelspringer.atlassian.net/browse/TIPPI-1094

[Copilot]

Pull request overview

This PR removes backup files and adds Prettier for code formatting. The changes standardize code formatting across the project by introducing Prettier configuration and tooling while cleaning up obsolete backup directories.

• Removes extensive backup directory containing obsolete doPlugins, whoami, superbounce, and other legacy code files
• Adds Prettier as a development dependency with formatting scripts
• Includes Prettier VS Code extension recommendation for consistent editor experience
• Applies Prettier formatting to one active JavaScript file (braze_checkout_tracking.js)

Reviewed changes

Copilot reviewed 81 out of 85 changed files in this pull request and generated no comments.

File	Description
package.json	Adds Prettier dependency and npm scripts for formatting
extensions/welt/braze_checkout_tracking.js	Reformatted with Prettier for improved readability
backup/* (multiple files)	Removed obsolete backup files
.vscode/extensions.json	Added Prettier VS Code extension recommendation

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[Copilot]

Pull request overview

Copilot reviewed 92 out of 96 changed files in this pull request and generated 1 comment.

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[Copilot]

While the comment explains disabling this rule for Prettier, consider documenting which Prettier configuration is being used and ensuring the .prettierrc or equivalent configuration file is present in the repository to maintain consistency.