Editoast fix memory consumption 🚀

[flomonster]

close #3122

• Force close idle connection (to free libpq allocation)
• Split the query to retrieve a railjson

Benchmark to retrieve a railjson from a large infra

Version	Time (seconds) w/o ext	Time (seconds) w/ ext
dev	13	12
split + deserialization	9	?
split + no deserialization	6	4

[codecov]

Codecov Report

Merging #3815 (c56cb36) into dev (cc83322) will increase coverage by 0.02%.
The diff coverage is 88.23%.

@@             Coverage Diff              @@
##                dev    #3815      +/-   ##
============================================
+ Coverage     69.77%   69.80%   +0.02%     
  Complexity     2016     2016              
============================================
  Files           439      439              
  Lines         21951    21976      +25     
  Branches       1662     1662              
============================================
+ Hits          15317    15340      +23     
- Misses         5839     5841       +2     
  Partials        795      795              

Flag	Coverage Δ
editoast	74.97% <88.23%> (+0.11%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
editoast/src/main.rs	6.81% <0.00%> (-0.11%)	⬇️
editoast/src/views/infra/railjson.rs	89.79% <93.75%> (+5.18%)	⬆️

... and 1 file with indirect coverage changes

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.