gqltest: add integration test for external code host links

Created by: unknwon

Fixes #16206

Created by: codecov[bot]

Codecov Report

Merging #16231 (f385303) into main (94173d0) will increase coverage by 0.00%. The diff coverage is n/a.

@@           Coverage Diff            @@
##             main   #16231    +/-   ##
========================================
  Coverage   52.96%   52.96%            
========================================
  Files        1649     1649            
  Lines       82442    82442            
  Branches     7364     7481   +117     
========================================
+ Hits        43668    43669     +1     
  Misses      34929    34929            
+ Partials     3845     3844     -1     

Flag	Coverage Δ
go	52.56% <ø> (+<0.01%)
integration	29.15% <ø> (ø)
storybook	28.00% <ø> (ø)
typescript	53.94% <ø> (ø)
unit	35.98% <ø> (ø)

Impacted Files	Coverage Δ
cmd/repo-updater/repos/types.go	68.75% <0.00%> (-0.63%)
.../internal/codeintel/resolvers/graphql/locations.go	85.56% <0.00%> (+2.06%)