change the if statement to not require a variable with a length > 0 and add a filter to json for the redis host

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

fix for a typo

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Related to: https://matrix.org/blog/2023/07/bridges-security-updates/

This reverts commit f98f803b44.

As the docker image has been released for this version we can now upgrade to this version

This reverts commit 428f7a1f75.

Looks like it won't become a tagged image until a "release" is posted.

Warning! Potentially breaking change: https://github.com/matrix-org/matrix-hookshot/releases/tag/3.0.0

Fixup for 7e2e2626a0

Some references were left unrenamed which caused `validate_config.yml`
to trigger.

Supersedes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2256

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2256

We expect `--tags=start` to handle systemd reloading, so we don't need
to do it manually each time we install/uninstall a .service file.

- forego removing Docker images - it's not effective anyway, because it
  only removes the last version.. which is a drop in the bucket, usually

- do not reload systemd - it's none of our business. `--tags=start`,
  etc., handle this

- combine all uninstall tasks under a single block, which only runs if
  we detect traces (a leftover systemd .service file) of the component.
  If no such .service is detected, we skip them all. This may lead to
  incorect cleanup in rare cases, but is good enough for the most part.

These `init.yml` (now `inject_into_nginx_proxy.yml`) tasks do not need
to `always` run. They only need to run for `setup-all` and
`setup-nginx-proxy`. Unless we're dealing with these 2 tags, we can
spare ourselves a lot of work.

This patch also moves the `when` statement from `init.yml` into
`main.yml` in an effort to further optimize things by potentially
avoiding the extra file include.

This fixes a regression since the change done in c1c152f7ac.
When another role (say `matrix-jitsi`) included `roles/custom/matrix-base/tasks/util/ensure_openssl_installed.yml`,
which then included `{{ role_path }}/tasks/util/ensure_openssl_installed_DISTRO.yml`,
that `role_path` variable would end up being the parent role
(`matrix-jitsi`) and not the `matrix-base` role, so we'd get a failure.

An alternative solution may have been to avoid using `role_path`, but
importing roles properly (like we've done in this patch) sounds like a better way.

Unfortunately, `import_role` fails if `tasks_from` is something like
`util/ensure_openssl_installed` (containing a `/`), so I had to move
these utils out of `util/`.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2228