support healthchecks configuration for nodes

[steiler]

implementing #1421 for podman and docker. containerd does not support healthchecks

• Docs are missing (@hellt can you cover that?!)
• schema should be double checked.

[codecov]

Codecov Report

Attention: 11 lines in your changes are missing coverage. Please review.

Comparison is base (ce1f20c) 48.48% compared to head (684b3c5) 50.36%.

❗ Current head 684b3c5 differs from pull request most recent head 7697eac. Consider uploading reports for the commit 7697eac to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1426      +/-   ##
==========================================
+ Coverage   48.48%   50.36%   +1.88%     
==========================================
  Files         147      147              
  Lines       14230    14271      +41     
==========================================
+ Hits         6899     7188     +289     
+ Misses       6560     6299     -261     
- Partials      771      784      +13     

Files	Coverage Δ
clab/config.go	67.41% <100.00%> (+0.83%)	⬆️
runtime/docker/docker.go	67.77% <100.00%> (+0.43%)	⬆️
types/node_definition.go	95.00% <100.00%> (+0.10%)	⬆️
types/types.go	64.86% <100.00%> (+4.86%)	⬆️
types/topology.go	67.97% <66.66%> (-0.04%)	⬇️
runtime/podman/util.go	56.59% <12.50%> (+41.71%)	⬆️

... and 10 files with indirect coverage changes

[hellt]

thanks @steiler
docs and schema fixed/added.