core: convert requestIds before sending to backend

[patrickhulce]

#5451 changed our network request ID such that many more IDs had the :redirect scheme than before, the DT backend has no notion of these fake <requestId>:redirect IDs and we always should have been cleansing them to be regular requestIds.

[paulirish]

looks like we can do this on our Network.getResponseBody call, too. it's used by response-compression and scripts gatherers.

[patrickhulce]

looks like we can do this on our Network.getResponseBody call, too. it's used by response-compression and scripts gatherers.

They both use the getRequestContent method on driver, we should be fine?

[paulirish]

this should fix these errors on paulirish.com