Feat: IPFS pinning form improvements

[sbauch]

The IPFS pinning form is currently an uncontrolled form that utilizes the onSubmit event to pin the name, description and asset to IPFS. It then opens a mint transaction on success, using the returned hash to mint a token.

Lots of improvements needed here -

• Ability to add custom key / value form rows for custom metadata
• Loading state for IPFS pinning
• Preview pinned data before mint for review
• Error handling - lots of pinning timeouts in dev