Remove most doxygen file-level commands, copyrights, and authors

Remove the \file directive, as it is always superfluous  because the
current file is implicit [1]:

> If the file name is omitted (i.e. the line after \file is left blank)
> then the documentation block that contains the \file command will belong
> to the file it is located in.

Author names and e-mails are not relevant for us: it can always be
inferred from git blame, and is often outdated.

Eurecom code has been contributed and was under OAI PL v1.0/v1.1.

For the cpack package contact: put generic email address that is
independent of an individual and that will remain reachable.

[1] https://www.doxygen.nl/manual/commands.html#cmdfile

openair3/NAS/TEST/NETWORK/network_parser.c

@@ -20,9 +20,6 @@
  */
 
 /*****************************************************************************
-      Eurecom OpenAirInterface 3
-      Copyright(c) 2012 Eurecom
-
 Source    network_parser.c
 
 Version   0.1
@@ -33,8 +30,6 @@ Product   Network Simulator
 
 Subsystem Command line parser
 
-Author    Frederic Maurel
-
 Description Command line parser of the Network Simulator process
 
 *****************************************************************************/

openair3/NAS/TEST/NETWORK/network_parser.h

@@ -20,9 +20,6 @@
  */
 
 /*****************************************************************************
-      Eurecom OpenAirInterface 3
-      Copyright(c) 2012 Eurecom
-
 Source    network_parser.h
 
 Version   0.1
@@ -33,8 +30,6 @@ Product   Network simulator
 
 Subsystem Command line parser
 
-Author    Frederic Maurel
-
 Description Command line parser of the Network Simulator process
 
 *****************************************************************************/

openair3/NAS/TEST/NETWORK/network_simulator.c

@@ -20,9 +20,6 @@
  */
 
 /*****************************************************************************
-      Eurecom OpenAirInterface 3
-      Copyright(c) 2012 Eurecom
-
 Source    network_simulator.c
 
 Version   0.1
@@ -33,8 +30,6 @@ Product   Network simulator
 
 Subsystem Network simulator main process
 
-Author    Frederic Maurel
-
 Description Implements the network simulator running at the network
     side for NAS_UE testing purpose.