adds support for __clabNodeName__ magic var

[hyposcaler-bot]

Adds clabNodeName

Should work for node/kind/default as described/asked in #1931

Added some primitive unit test for it in config_test.go
Also updates doc/manual/nodes.md mostly by copying the basic flow and content for the notes on clabNodeDir

[hellt]

OOO this week, will get to it once I am back
thank you!

[kaelemc]

OOO this week, will get to it once I am back

@hellt that is sure one long week 😅

I took the liberty of trying it out myself.

This is honestly brilliant, I tested __clabNodeName__ under defaults: and under each node individually, working perfectly.. seems like this makes the configs much easier.

@hyposcaler-bot nice work, nothing else to say, it does exactly what it says on the box 👍

[hellt]

a week became a month :D sorry
waiting for the pipeline to finish and then merging this beauty

[codecov]

Codecov Report

Attention: Patch coverage is 12.00000% with 22 lines in your changes missing coverage. Please review.

Project coverage is 51.86%. Comparing base (9e96472) to head (eb74eee).
Report is 70 commits behind head on main.

Files with missing lines	Patch %	Lines
mocks/mocknodes/default_node.go	0.00%	18 Missing ⚠️
mocks/mocknodes/node.go	0.00%	3 Missing ⚠️
mocks/mockruntime/runtime.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2257      +/-   ##
==========================================
+ Coverage   51.18%   51.86%   +0.68%     
==========================================
  Files         172      172              
  Lines       16689    17256     +567     
==========================================
+ Hits         8542     8950     +408     
- Misses       7235     7366     +131     
- Partials      912      940      +28     

Files with missing lines	Coverage Δ
clab/config.go	67.69% <100.00%> (+1.03%)	⬆️
mocks/mockruntime/runtime.go	10.22% <0.00%> (-0.38%)	⬇️
mocks/mocknodes/node.go	5.12% <0.00%> (ø)
mocks/mocknodes/default_node.go	0.00% <0.00%> (ø)

... and 58 files with indirect coverage changes