feat/add NftPlaceholder component with rough outline

[kraftjs]

Summary

Please summarize your changes, describing what they are and why they were made.

Media for NFTs will not be supported until completion of E12.M3. Until then, we will need a placeholder to show the NFT type. This placeholder will also be helpful after delivering E12.M3 while awaiting fetching of NFT data or if data is unavailable.

This placeholder will need to change depending on the NFT MimeType. It will also appear in the NFT details view, in the NFT gallery view, and in the send | receive | and activity flows of the wallet tab. I suggest an extra small, small, medium, large, extra large prop type to handle for this.

• nft dropdown send options (extra small)
• activity feed (small)
• confirm send, receive, claim (medium)
• gallery view and collection overview (large)
• details view (extra large)

For now, just use a text placeholder. But a more long term solution is to create icons for each of the parent mime types.

Can expand in the future once we add media.

Changelog

- Created NftPlaceholderIcon component
- Created NftMediaContainer component

Relevant Issues

Please list any related issues using development keywords.

Closes #4910

Testing

Platforms

Please select any platforms where your changes have been tested.

• Desktop
  • MacOS
  • Linux
  • Windows
• Mobile
  • iOS
  • Android

Instructions

Please describe the specific instructions, configurations, and/or test cases necessary to test and verify that your changes work as intended.

...

Checklist

Please tick all of the following boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or modified tests that prove my changes work as intended
• I have verified that new and existing unit tests pass locally with my changes
• I have verified that my latest changes pass CI workflows for testing and linting
• I have made corresponding changes to the documentation

[nicole-obrien]

Just some minor changes

[nicole-obrien]

LGTM! Can update further as we develop the nft activities and the media pages