[BUGFIX] fix link type detection by different sources

[genofire]

Description

Motivation and Context

ffnord/mesh-announce#25

Checklist:

• My code follows the code style of this project.
• I have added also tests for my new code.

[codecov-io]

Codecov Report

Merging #109 into master will increase coverage by 8.98%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master     #109      +/-   ##
==========================================
+ Coverage   74.48%   83.47%   +8.98%     
==========================================
  Files          41       37       -4     
  Lines        1305     1216      -89     
==========================================
+ Hits          972     1015      +43     
+ Misses        314      185     -129     
+ Partials       19       16       -3

Impacted Files	Coverage Δ
output/meshviewer/graph.go	100% <100%> (ø)	⬆️
output/meshviewer-ffrgb/meshviewer.go	90.62% <60%> (-9.38%)	⬇️
output/all/filter.go	100% <0%> (ø)	⬆️
output/all/output.go
cmd/query.go
cmd/serve.go
cmd/import.go
database/all/connection.go
lib/jsontime/jsontime.go
lib/duration/duration.go
... and 11 more