fix(planner): Lambda body can be a field selection

[dbuduev]

Fix #1719

[codecov]

Codecov Report

Merging #1720 (a98a225) into main (cedf358) will increase coverage by 0.20%.
Report is 1 commits behind head on main.
The diff coverage is 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1720      +/-   ##
==========================================
+ Coverage   52.94%   53.15%   +0.20%     
==========================================
  Files         133      133              
  Lines       15715    15716       +1     
==========================================
+ Hits         8321     8354      +33     
+ Misses       6665     6633      -32     
  Partials      729      729              

Files Changed	Coverage Δ
internal/engine/planner/ast.go	67.62% <0.00%> (-0.12%)	⬇️

... and 5 files with indirect coverage changes