IssueTracker

RemoteMediator requires a lot of duplication of effort with PagingSource.

Let's explore creating a simpler RemoteMediator API based on PagingSource, which sacrifices a little customizability for an extremely simple API, similar to early explorations.

For inspiration here, see also Store's SourceOfTruth.of(): https://github.com/dropbox/Store#fully-configured-store

The item-keyed variant could look something like the following (would need another variant to handle key storage):

RemoteMediator.from(
    sourceFactory = { NetworkPagingSource() }
    keyProvider = { networkItem -> networkItem.id }
    store = db.itemDao()::storeData // manually implemented on dao to handle transactions, etc
)