Update Certmanager to 0.10.1

Fixes: #1568 (closed)

We jump to 0.10.1 instead of even newer as the customer resources we have been using where removed in 0.11 (deprecated in 0.8). Once we know that users have upgraded their issuers by upgrading to this release, we can continue to move forward to new versions.

• In order to continue a smooth upgrade process, I have embedded the certmanager CRDs in our chart. While certmanager has moved to required users to install them using kubectl before running helm. Before doing this, they had first moved to installing them with helm using crd-hook, which both us and them makes it so you cannot upgrade the crds through helm. Luckily we never took the update that moved it to a hook, and our issuers is already created later in a job, so we can simply embed the crds like they were previously for now. In the future when move to helm 3, or GA our own operator, we will likely once again change how CRDs are installed

• https://cert-manager.io/docs/installation/upgrading/upgrading-0.8-0.9/ introduced a change that requires the existing certmanager deployments to be deleted before upgrading. I have worked around this by overriding the certmanager chart name, from certmanager to cert-manager. This results in helm deleting all the old resources for us, and creating new ones, giving us the same effect.

• Our issuer resource has been updated to the new syntax. Certificates will be as well when they renew.

• Jetstack now uses their own helm repo to host the chart. This doesn't impact our end users using our repo, as packaging our chart takes care of fetching the dependency, but our CI, and dev docs were updated to reflect the changes needed when working with the checked out repo. And also this MR is needed in our chart repository for release: charts/charts.gitlab.io!141 (merged)