Use the builder client to fetch the approval data

The `handleInitiateTPItemsApprovalFlow` should use the builder-client instead of directly fetching that from the builder server.
For this we need to:
- [ ] Update the builder client so it can fetch approval data for a collection
- [ ] Release it and update the dependency here
- [ ] Update the saga on `collection/sagas.ts` to use the new builder client version
- [ ] Remove the unused builder.ts method

We might need an issue to track this on the builder-client side of things. We can just reference this issue for now

Start with handleInitiateTPItemsApprovalFlow in collection/sagas.ts and inspect the existing builder.ts method that fetches approval data. Check the builder-client changes and dependency release needed for collection support, then update the saga and remove the unused method; done means the saga uses the released builder client for collection approval data.

Written by the indexing model from the issue text.