feat: add new trigger-renovatebot job

See merge request !107

Add a new CI job to the common pipeline which triggers a run of
renovatebot for the CI pipeline's project if the
TRIGGER_RENOVATEBOT_ENABLED variable is set.

Since no jobs are added *unless* that variable is set, this ensures that
renovatebot runs are always explicitly triggered.

The auto-devops/trigger-renovatebot.yml template also includes a
template CI job which can be used to construct trigger jobs with more
elaborate rulesets.

fix: container scanning when using multi target docker images

See merge request !106

Combined maven pipeline configs from WRS and Java Common into a new common template

See merge request !104

fix(multi-target-docker-images): set env variables through before_script

See merge request !105

fix(multi-target-docker-images): split logic into multiple files

Closes #90

See merge request !103

chore: Configure Renovate

See merge request !95

fix(common-pipeline): correct include path for auto-devops template

See merge request !102

fix: correction to the documented ci template path for auto-devops.gitlab-ci.yml

See merge request !101

chore: rename `review` stage to match gcp workspace naming

See merge request !100