Add support for account icons via metadata

[bootarou]

Summary

I would like to propose a feature that displays account icons using image URLs stored as Symbol account metadata.

Proposed Feature

• This feature adds support for rendering account icons from metadata associated with a Symbol address.
• Metadata key used: social_meta_data (image URL)

Implementation Status

• I have already implemented a working prototype in my fork:
  🔗 https://github.com/bootarou/explorer-smd

Benefits

• Enhances the user interface with richer visuals.
• Makes the explorer more user-friendly by showing recognizable icons for accounts.
• Supports decentralized identity by associating visuals with addresses.

Notes

I am happy to adjust the implementation based on feedback or contributor guidelines.
Please let me know your thoughts!