fix(router): traditional router could error with "invalid order function for sorting"

[bungle]

Summary

The same route may have been added multiple times to routes_by_sources[<ip|port>] or routes_by_destination[<ip|port>] which lead to "invalid order function for sorting" when we tried to sort the routes. There was also sorting issue when multiple routes sorted the same. This fixes the issue.

KAG-918

Issues Resolved

Fix #10446
Close #10470

[bungle]

@sabertobihwy and @zhangzerui20,

What are your thoughts on this alternate implementation?

Perhaps we can check if we have other structures too where we add same route when not needed.

[ghost]

I reviewed this PR and understood the fix and it's great!

[ghost]

Perhaps we can check if we have other structures too where we add same route when not needed.

I have tried some combinations locally with no problems.

BTW, the idea of tried is to make routes_by_destination appear as a table with duplicate references, e.g.:

["0.0.0.0"] = { <table 2>, <table 1>, <table 1>, <table 1>
    [0] = 4
  }

now this PR works well.

[bungle]

@chronolaw / @sabertobihwy, feel free to approve if you think it is fine.