Allow coprocessors to modify path in RouterService

[lleadbet]

Is your feature request related to a problem? Please describe.

Coprocessors today are able to read the query parameters of a request using the path. For some use-cases, these parameters need to be modified for one reason or another. For example, some may use a custom implementation of APQs over GET requests, and it is needing to be coerced into a format the router can use.

Describe the solution you'd like

The path parameter can be updated in RouterService such that it is re-evaluated for APQ purposes.

Describe alternatives you've considered

Putting a transform layer in front of the router to handle this logic.