Pass all group bank items in extra JSON on group bank transaction

[APKiwi]

Checklist

• [x] I've searched the issues and pull requests for similar looking suggestions.
• [x] I've checked the Unreleased section of the changelog for newly added features that sound like my suggestion.

Describe your Suggestion

I'd like to propose sending the contents of the group bank, perhaps along side "deposits" and "withdrawals" on the JSON.extra object might have "itemsInGroupStorage".

This would be a comprehensive list of all items that are left in the bank after the transaction.

Reasoning

To combat the increased use of OSRS on mobile, and events which are not sent by Dink (and occasionally connection issues, timeouts or server-side downtime) - it would be awesome to have the contents of the bank passed every time someone makes a transaction to allow external systems to keep track or remedy current banked item disparity. This would allow us to keep (or 'fix') the storage in sync externally where possible.

[APKiwi]

I suppose further to this it only really needs to happen on the first event per login - if that's easier/less load heavy?

Could expand to include the users own bank too (once per login).

[iProdigy]

Would it be fine if this data was only sent to the metadata notifier? Apologies for the delay in replying to this request

[APKiwi]

All good!

Yes, at least for my use-case there is no need to submit a separate event. Submitting this to the metadata notifier will allow us to process this as desired