Run tests Docker in Docker (#261)

* Try running tests in Docker

* Spawn new container for each test

* Store test artifacts outside of mount

* When requested, build up to date image in test script

* sudo is unneccessary in containerized test env

* Skip azure test

* Backdate fixture file in JSON database

* Pin versions for azure tools

* Mount temp volume for /var/lib/docker to prevent dangling ones created by VOLUME instruction

* Fail backdating tests with message

* Add some documentation on test setup

* Cache images

* Run compose stacks with shortened default timeout

test/Dockerfile

@@ -0,0 +1,13 @@
+FROM docker:24-dind
+
+RUN apk add \
+  coreutils \
+  curl \
+  gpg \
+  jq \
+  moreutils \
+  tar \
+  zstd \
+  --no-cache
+
+WORKDIR /code/test