Move reconnect-strategy.yang into controller

With the protocol framework migrated into the controller (opendaylight/commons/protocol-framework), there is no reason to carry the reconnect-strategy configuration binding in the bgpcep project (bgp/rib-impl-config/src/main/yang/reconnect-strategy.yang and friends).

Move all of it directly into the protocol framework, with a new module name (odl-protocol-framework-cfg.yang) and appropriate namespace changes. Once it has been merged there, elimininate it from bgpcep repository