Configurable proxy options for rewrites

[imZack]

Describe the feature you'd like to request

Currently, there is no way to configure the proxy options for the "rewrites" function. For instance, if I want to disable x-forward-x headers, it's hard coded with option xfwd: true.

Describe the solution you'd like

I think making the new Proxy({options}) configurable would be a way that users can easily customize the proxy's behavior.

Describe alternatives you've considered

OR making the proxy instance replaceable (injecting from next.conf.js?)

[bbeck10]

I have a draft PR here - #40277

[lukeocodes]

@bbeck10 did this ever get resolved? this would have been extremely useful functionality