Enable Sidebar Drag and Drop Upload along with Multi-level Support

[sam-shubham]

[#3086] Enable Sidebar Drag and Drop with Multi-level Uploads

Enhanced the Sketch Files sidebar to support drag-and-drop file uploads, improving accessibility and workflow.

Details:
• Introduced a wrapper component to handle drag-and-drop functionality.
• Enabled multi-level uploads, allowing files to be uploaded into nested directories.
• Updated initSidebarUpload to dynamically initialize uploads for the active folder or root directory.
• Integrated drag-and-drop by wrapping <ConnectedFileNode> with a SidebarFileDragDropUploadWrapper for seamless uploads.

Improvements:
• Simplified the file upload process by removing the need for [+] > [Upload File].
• Enhanced user feedback with dynamic drag-over messages.

This update improves user workflow and sets the foundation for future features like cross-sketch file duplication.

Fixes #3086

Changes:
• Added the SidebarFileDragDropUploadWrapper component for drag-and-drop functionality.
• Updated initSidebarUpload to handle parent directory setup for multi-level uploads.
• Enhanced Redux state management to store the parentId for initiated sidebar uploads.
• Integrated dropzone-related event handling in uploader.js.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123

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[raclim]

Sorry that it took a while to get to review this and thanks so much for taking the time to look into this feature!

Although I think that what's set up here is a great start, I'm not able to see the file uploaded when I try to drag it into the sidebar. I also feel that we might need to take a step back before starting development and thinking through what the design of this might look like? I'll try to list in the PR a list of steps that we might need before completing this feature.

Since this PR isn't complete and we have a larger queue at the moment, I'm going to close this for now. I'm sorry that we couldn't get this in, but please feel free to continue working on this issue or check our other ones out!