fix: allow IEventSubSocket#register with null transport

[iProdigy]

Prerequisites for Code Changes

• This pull request follows the code style of the project
• I have tested this feature

Issues Fixed

• Allow eventsub subscriptions to be registered with null EventSubTransport (EventSubSubscription#setTransport in TwitchEventSocket#register was not reflected in SubscriptionWrapper)

Changes Proposed

• SubscriptionWrapper should delegate getters to the held EventSubSubscription rather than copying the fields, which ensures any setters called on the underlying subscription are reflected in the wrapper (and reduces memory consumption)