feat: implement container keep-alive feature

- Add `keep_alive` parameter to `container_start`
- Implement logic to restart containers with `tail -f /dev/null` after successful entrypoint exit
- Update `podman_pull_and_export` to also extract image metadata
- Enhance `create_crun_config` to use extracted image metadata (ENTRYPOINT, CMD, ENV)
- Refactor test suite to use `keep_alive: true` for Alpine containers

test_basic.vsh

@@ -171,6 +171,7 @@ lib/core
 lib/develop
 lib/hero/heromodels
 lib/virt/heropods
+lib/virt/crun
 '
 
 // the following tests have no prio and can be ignored