[Routing] fix inconsistencies in RequestContext
[Routing] add tests for RequestContext
Merge branch '2.3' into 2.5

* 2.3:
  [Routing] add tests for RequestContext
  [Routing] fix inconsistencies in RequestContext
  don't raise warnings when exception is thrown
Merge branch '2.5'

* 2.5:
  [Routing] add tests for RequestContext
  [Routing] fix inconsistencies in RequestContext
  don't raise warnings when exception is thrown
  [Framework][DX] Set the proper validator class according to the configured api version
[Routing] unify fluent interface in RequestContext