feat: full page pivot for report editor

[AdityaHegde]

Adds routes for report create and edit pages. Has sub routes for rendering pivot for selected explore. Sub routes for canvas will be added in a future PR.

Closes APP-490

Checklist:

• [ ] Covered by tests
• [x] Ran it and it works as intended
• [x] Reviewed the diff before requesting a review
• [x] Checked for unhandled edge cases
• [x] Linked the issues it closes
• [ ] Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• [ ] Intend to cherry-pick into the release branch
• [ ] I'm proud of this work!