Show only active ports by default in port listings

[arjunsalyan]

I am trying to break #122 so that the bug can be fixed without being delayed due to the "Include deleted ports" filter.

[codecov]

Codecov Report

Merging #127 into master will increase coverage by 0.07%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #127      +/-   ##
==========================================
+ Coverage   73.84%   73.91%   +0.07%     
==========================================
  Files          46       46              
  Lines        1338     1342       +4     
==========================================
+ Hits          988      992       +4     
  Misses        350      350

Impacted Files	Coverage Δ
app/ports/views.py	57.75% <100%> (ø)	⬆️
app/ports/models/port.py	88.66% <100%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bafaefc...bf9be84. Read the comment docs.

[mojca]

When we implement more general filters we could probably improve / generalize the code a bit, but it looks fine for now.