fix(performance): lazily load expensive modules in aurweb.db functions

This "fix" is a bit of a hack to remove the extra delay caused by importing aurweb modules in the aurweb.db script, used by standalone Git scripts. This solution was derived from !500 (closed)

Before this (or !500 (closed)) is merged, we should create an issue describing the import speed issue and some possible workarounds: https://peps.python.org/pep-0690/ has been brought up by @foutrelis and is essentially what was done in this MR without the lazy load module.