Now, we use an equivalent query to PHP's query, yet we grab
every piece of data we need for all packages asked for in one
database query.

At this time, local benchmarks have shown a slight performance
improvement when compared to PHP.

fastapi 262 requests/sec
php 250 requests/sec

Extras:

- Moved RPCError to the aurweb.exceptions module

Signed-off-by: Kevin Morris <kevr@0cost.org>