If a global vector-sink property on the logs plugin is set, we will use that to configure a log sink (defaulting to console output otherwise). Note that the actual configuration still needs to be a valid DSN representing a Vector log sink.
While this does not support pinning log sinks to specific apps, it opens up integration for those who use a single k3s cluster in shared tenancy.
Dokku uses a few external images for various bits of functionality, but these must be manually updated every so often due to being referenced in code.
By moving the references to Dockerfiles, we can take advantage of dependabot to issue automatic PRs when they are out of date.
Using compose instead of manual docker calls allows folks to customize the vector container by using a custom compose.yml template file. This opens us up to more customizations while aligning container management with how we do other external containers (such as for the proxy plugins).
Refs #5784
Not all properties can be set globally, and the "appName" in the global case is currently defaulted to `--global`. This is okay because domain label names cannot start with hyphens, and all app names must be valid domain label names.
