Add documentation for the alternative logging storage.

This covers basic setup for configuring LAVA logging in
MongoDB, Elasticsearch and Google firestore as well as how
to copy the logs from the filesystem to the database.
15 jobs for logging-db-docs in 16 minutes and 8 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #106536
amd64
dispatcher-debian-10

00:03:27

passed #106538
amd64
dispatcher-debian-11

00:03:19

passed #106537
amd64
server-debian-10

00:03:45

passed #106539
amd64
server-debian-11

00:06:23

 
  Analyze
passed #106540
amd64-dind
bandit-sast

00:00:53

passed #106541
amd64
black

00:00:40

passed #106542
amd64
code_quality

00:00:27

passed #106543
amd64
coverage

00:06:15

59.33%
passed #106544
amd64
dockerfiles

00:00:22

passed #106546
amd64
pylint

00:03:02

passed #106545
amd64
schemas

00:00:35

 
  Build
passed #106548
amd64
debian/10

00:02:26

passed #106547
amd64
doc

00:01:16

passed #106549
amd64-dind
docker-amd64-dispatcher

00:02:38

passed #106550
amd64-dind
docker-amd64-server

00:03:25