NTX Builder: Prune strategy for notes

In https://github.com/0xMiden/node/pull/1892 I propose to store the committed notes in the NTX builder store, this causes some duplication with the store component.

We could try a couple different approaches to address this:

- We could add a timestamp to the entries, and considering that this endpoint is meant for debugging we can prune every period of time the old entries.
- Another option could be to check in the RPC component if we have that note committed in the store component before sending the request to the NTX builder.