Given the user can soon have multiple config sources for CI, we now store
what type at the time of the pipeline run we chose. This will give us
insight into what triggered the new pipeline so we can display it to the
enduser.

Behind an application setting, which defaults to false, this commit
implements the implied CI/CD config. Which means that in the case we
can't find the `.gitlab-ci.yml` on the commit we want to start a
pipeline for, we fall back to an implied configuration.

For now the Bash template has been copied to
`Auto-Devops.gitlab-ci.yml` so the tests actually work.

Fixes #34777

It was missing and expected it wouldn't hurt anyone

`:mailer` is needed to pick it easily, while
`type: :mailer` is needed for picking it automatically for
tests located in spec/mailers/*_spec.rb

It's a bit complicated in spec/services/notification_service_spec.rb
but we'll leave it alone for now.

Remove superfluous lib: true, type: redis, service: true, models: true, services: true, no_db: true, api: true
Signed-off-by: NRémy Coutable <remy@rymai.me>

When sending the usage data, it now includes all pipelines. This commit
will split the pipelines in two; internal and external.

This will lead to historical data being incorrectly marked this way.

Fixes gitlab-org/gitlab-ce#33172

So that we could use it for the schedule before
trying to use CreatePipelineService

* implemented logging of project and system web hooks
* implemented UI for user area (project hooks)
* implemented UI for admin area (system hooks)
* implemented retry of logged webhook
* NOT imeplemented log remover

Make it gracefully handle unexisting pipelines and refactor iterating
all the merge request paths.

And add some specs.

Turn ExpirePipelineCacheService into Worker so it can fetch all the
merge requests for which the pipeline runs or did run against.