add missing promptToCreateSolanaAccount flag

[adonesky1]

Explanation

If solana is a requested scope but not supported, we add a promptToCreateSolanaAccount metadata flag to forward to the connection UI

See designs here for the "opt in" flow this enables

References

Extension PR - since currently extension has its own wallet_createSession handler. We'll consolidate these soon

Changelog

@metamask/multichain-api-middleware

• Added: when wallet_createSession is called with solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp as a requested scope, but there are not currently any accounts in the wallet supporting this scope, we add a promptToCreateSolanaAccount to a metadata object on the requestPermissions call.

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes