Global "allowReservedInQueryParameters" flag

[briangweber]

Is your feature request related to a problem? Please describe.
We are migrating from the old swagger-tools library, which is much more permissive of reserved characters in the querystring. Express handles these parameters just fine either encoded or unencoded, so while best practices should be to encode query parameters, this validation is overly strict for our usage.

Describe the solution you'd like
A global setting possibly under validateRequests to allow reserved characters in all query parameters.

Describe alternatives you've considered
We could add allowReserved to all query parameters, but it is easy to miss them which can easily cause a production outage as clients start receiving 422 errors for previously permissible requests (happened today - user was passing 1234+ABC for a postal code).

Additional context
I'm happy to collaborate on a fix or implement it with some guidance - I don't see a way to thread global settings through to the location where validation seems to be happening