Add database backend (SQLite) (#26)

Add database with background information for each pkgbase, for possible future use.
A static status page is generated from the db.

Currently includes:

* sub-packages
* build-time
* build-duration
* status (failed, latest, skipped, queued, building, build)
* version (both from PKGBUILD and repo)
* last checked

Database is currently only used for informational purposes. Goal is to refactor many (expensive) methods to use the db instead of searching/parsing files.

Reviewed-on: https://git.harting.dev/anonfunc/ALHP.GO/pulls/26
Co-authored-by: Giovanni Harting <539@idlegandalf.com>
Co-committed-by: Giovanni Harting <539@idlegandalf.com>

config.yaml

@@ -13,6 +13,7 @@ basedir:
   chroot: /var/lib/alhp/chroot/
   makepkg: /var/lib/alhp/makepkg/
   upstream: /var/lib/alhp/upstream/
+  db: /var/lib/alhp/alhp.db
 
 march:
   - x86-64-v3