Dashboard: Migrate Batch Upload NFTs from chakra to tailwind, UI improvements (#7689)

<!--

## title your PR with this format: "[SDK/Dashboard/Portal] Feature/Fix: Concise title for the changes"

If you did not copy the branch name from Linear, paste the issue tag here (format is TEAM-0000):

## Notes for the reviewer

Anything important to call out? Be sure to also clarify these in your comments.

## How to test

Unit tests, playground, etc.

-->

<!-- start pr-codex -->

---

## PR-Codex overview
This PR focuses on refactoring and enhancing the `FilePreview` component, improving the upload process for NFTs, and updating various components to utilize the new structure. Several files related to example CSVs were deleted, and new features were added for better file handling.

### Detailed summary
- Deleted example CSV files.
- Added `FilePreview` import in multiple components.
- Enhanced `FilePreview` styling and functionality.
- Updated `DownloadFileButton` to accept additional props.
- Refactored `BatchTable` to improve pagination and display logic.
- Improved `UploadStep` for better user experience during file uploads.
- Introduced `DelayedRevealConfiguration` and `SelectReveal` components for managing NFT reveal types.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`

<!-- end pr-codex -->

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

* **Refactor**
  * Replaced Chakra UI and third-party libraries with a custom UI system across batch upload components for a more unified look and feel.
  * Simplified and restyled batch minting forms, tables, upload steps, and reveal configuration.
  * Updated drag-and-drop functionality to use a dedicated DropZone component.
  * Streamlined table rendering and pagination with manual state management and local UI components.
  * Improved layout, styling, and accessibility for option selection, shuffle toggle, and modal dialogs.
  * Enhanced media preview styling and standardized file preview imports for improved consistency.
  * Added tabbed format selection and enriched instructional content with downloadable CSV/JSON examples in the upload step.
  * Improved submit button placement and added help links for user guidance during batch minting.
* **New Features**
  * Added customizable button variants and styling options to the file download button for better UI flexibility.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: MananTank