nat: nat44-ed cleanup & fixes

Set deprecated option on unsupported API calls.
Cleaned up API calls with deprecated option. Removed
in progress option from long term used API calls.

Removed obsolete/unused nodes, functions, variables.

Fixed set frame queue nelts function. Calling API
would incorrectly not fail even though frame queue nelts
can only be set before first call nat44_plugin_enable.

Moved all formatting functions to _format.c file.

Type: refactor
Change-Id: I3ca16e0568f8d7eee3a27c3620ca36164833a7e4
Signed-off-by: Filip Varga <fivarga@cisco.com>