Wrappers: create the uplink and downlink wrappers

The downlink wrapper shall include:

• The downlink datapath (encoder)
• The Tx gearbox

The uplink datapath shall include:

• The uplink datapath (decoder)
• The Rx gearbox
• The frame aligner

Only one reset per wrapper, sequence is then managed internally.

To make the design easier to configure, implement and support, the dynamic mode has to be removed.