[kraken] Fix: Recursive display of line and routes

[kadhikari]

Before correction:

• Lines are displayed with routes recursively depending on depth: for depth=3 line.routes[].line.routes[]
• Routes are displayed with line recursively depending on depth: for depth=3 routes[].line.routes[].line
• with depth = 0 line doesn't have Network.

After correction

• Lines are displayed with routes not depending on depth: for depth=1, 2 and 3 line.routes[]
• Routes are displayed with line not depending on depth: for depth=1, 2 and 3 routes[].line
• Line will always have Network even with depth = 0.

For more details:

• https://navitia.atlassian.net/browse/NAV-2348
• https://navitia.atlassian.net/browse/NAV-2348?focusedCommentId=54235

Comparison of response time for some request on my PC before and after the correction:

• url_navitia/lines/rerc/lines?
  -> depth=1 : 12.5 ms -> 13.0 ms / 57.5 ko -> 57.5 ko
  -> depth=2 : 13.6 ms -> 12.7 ms / 80.4 ko -> 57.6 ko
  -> depth=3 : 70 ms -> 12.8 ms / 1.5 Mo -> 57.6 ko

• url_navitia/lines/rerc/routes?
  -> depth=1 : 15 ms -> 14.6 ms / 69.6 ko -> 75.8 ko (Network added in route.line)
  -> depth=2 : 76.5 ms -> 18 ms / 1.4 Mo -> 94.8 ko
  -> depth=3 : 393 ms -> 340 ms / 5.9 Mo -> 4.1 Mo (No change is made on route.stop_point and its sub-objects)

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

84.6% Coverage
0.0% Duplication

[SGrenet]

Ok, perf test are useful