feat: add lookup operation

[eddycharly]

Explanation

Add lookup operation.

Fixes #1034

[codecov]

Codecov Report

Attention: Patch coverage is 58.82353% with 21 lines in your changes are missing coverage. Please review.

Project coverage is 72.94%. Comparing base (11fe12f) to head (59029ca).

Files	Patch %	Lines
pkg/runner/processors/step.go	31.57%	4 Missing and 9 partials ⚠️
pkg/validation/test/lookup.go	42.85%	3 Missing and 1 partial ⚠️
pkg/validation/test/operation.go	33.33%	1 Missing and 1 partial ⚠️
pkg/validation/test/catch.go	90.90%	0 Missing and 1 partial ⚠️
pkg/validation/test/finally.go	90.90%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1089      +/-   ##
==========================================
- Coverage   73.12%   72.94%   -0.19%     
==========================================
  Files         129      130       +1     
  Lines        4499     4516      +17     
==========================================
+ Hits         3290     3294       +4     
- Misses        948      952       +4     
- Partials      261      270       +9     

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