Add possibility to add custom transport

[bfpepper87sentry]

Problem Statement

Right now there is not a custom transport option to send events over ONLY wifi. requesting that the iOS SDK mirrors the android SDK in this functionality

Solution Brainstorm

Similar to https://docs.sentry.io/platforms/android/configuration/options/#transport

Are you willing to submit a PR?

No response

[philipphofmann]

Do you want to be able to use a custom transport to send events to the sentry only via WIFI, @bfpepper87sentry? If yes, please explain your reasons. Maybe we can come up with a different solution, that doesn't require a custom transport.