Podman receiver: Replace official Podman bindings with custom REST client to monitor podman

[owais]

Is your feature request related to a problem? Please describe.
Podman receiver uses the official Podman library to interact with Podman daemon and extract metrics from it. The library is quite heavy and pulls in a lot of dependencies that the podman receiver does not really need. It depends on things like btrfs, gpgme, devicemapper, etc which make it inconvenient to build the collector on Linux and much harder (impossible?) to build it on other platforms. Luckily, we can use some build tags to exclude most of these dependencies as done here.

This does allow the collector to be built without pulling in those dependencies but it still causes some inconvenience.

• The collector build system needs to have special knowledge about build tags required by a specific component (podman receiver). We don't have a mechanism to auto-discover such component requirements today. We should arguably add it regardless as other components may require it in future but still, not having such requirements in the first place would be better/simpler.
• Makes it very hard for distros derived from this repository to build binaries and discover the problem/solution. Ex: Avoid usage of github.com/mtrmac/gpgme #5241

Describe the solution you'd like
Remove libpodman and replace it with a custom REST API client that does only as much as the receiver requires. It should still support all communication and auth mechanisms that the official library supports e.g, ssh.

Additional context
Podman has been requested to split their Go API bindings out of the core repo which should alleviate some of these problems but looks like it is not a priority at the moment. containers/podman#6866

This would also solve issues like this: #5414