Remove custom server initializer

[defagos]

Description

This PR removes the custom server initializer, fixing a regression introduced in version 7.0.0 which intended to keep it for a while (but as a result would not play any URN in debug builds).

Note that we could have kept the API somehow private but we still agreed that alternative server configurations currently offered by the demo (SAM, geoblocking) are not really useful. If really needed we can test such configurations in a debug build, tweaking URLs and request headers before.

Changes made

• Remove custom Server initializer.
• Remove all non-standard server configurations from the demo.

Checklist

• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).