Convert emac, cellular, and wifi targets, and enable one UDP test

Convert nanostack and lwipstack to STATIC libraries

lwiperf: fix double-free of pcb on error

tcp_out: fix tcp_output_fill_options() arguments

Add netbuf-recvinfo-enabled config to LWIP mbed_lib.json

LWIP: Provide inline replacements for htons() and htonl()

Adding documentation and minor code changes ...

Doxygen documentation for MsgHeaderIterator was added. Type used
for alignment of the nsapi_msghdr_t struct was changed.

Code improvements for the unresolved comments ...

This patch contains improvements mentioned in the unresolved PR
comments:
- function names were changed from socket_sendmsg/socket_recvmsg to
  socket_sendto_control/socket_recvfrom_control.
- default implementation of this functions was provided in the
  NetworkStack class.
- MsgHeaderIterator accesses elements on the aligned addresses.

New feature: send/recv message implementation added to network stack

Add LWIP Broadcast option for UDP socket.

Merge pull request #14342 from JojoS62/fix-lwIP-add_dns_server ...

use calloc for new_interface_server

replace underscore by hyphen

move private struct dns_server_interface to c file ...

use ip_addr function to initialize dns_add_interface_server

turn off rdnss for compatibility

add options to use RDNSS and IPv6 queuing

use calloc for new_interface_server ...

malloc left garbage in the structure, dns IPs were filled with random content

lwip: use adeguate mem-size for Portenta H7

Merge pull request #13671 from balajicyp/topic/setsockopt_ip_tos ...

Add an socket option to set type of service to set specific precedence for QoS

CMake: Rename CMake targets ...

* mbed-os renamed mbed-core
* mbed-os-<COMPONENT> renamed mbed-<COMPONENT>

CMake: Componentize Mbed OS into multiple CMake targets (#13732) ...

Aside from the core mbed-os CMake target, a number of targets have been created so they can optionally be included by application executables that require them using `target_link_libraries()`.

Co-authored-by: Martin Kojtal <martin.kojtal@arm.com>
Co-authored-by: Rajkumar Kanagaraj <rajkumar.kanagaraj@arm.com>

CMake: Fix build failure due to drivers and lwipstack dirs move

Remove erroneous character from SPDX identifer ...

Erroneous '/' was appended to start of comment. This was causing CMake
warning during complition. Removes character from affected files.

Add SPDX license identifier to Arm files ...

Add license identifier to files which Arm owns the copyright to,
and contain either BSD-3 or Apache-2.0 licenses. This is to address
license errors raised by scancode analysis.

Add nsapi types for IP TOS and fix opt length check

set ip type of service to set specific precedence for QoS

set ip type of service to set specific precedence for QoS

Added GR-MANGO to be a target. ...

Passed GreenTea CI.
Added RZ_A2XX and GR_MANGO to targets.json.
Added RZ_A2XX to mbedlib.json in lwipstack and netsocket/ppp.
Added TARGET_RZ_A2XX directory to targets/TARGET_RENESAS.
Added TARGET_RENESAS_EMAC directory to features/netsocket/emac-drivers.
Moved TARGET_RZ_A1_EMAC directory into the TARGET_RENESAS_EMAC directory below and renamed to TARGET_RZ_A1XX.
Added TARGET_RZ_A2XX directory to features/netsocket/emac-drivers/TARGET_RENESAS_EMAC.

Added argument-check to dns_get_interface_server. ...

Added argument-check to avoid accessing NULL pointer.
The second argument 'interface_name' of this function can be NULL.
And the argument 'interface_name' is used for the argument of strcmp() without checked.

For example, LWIP::add_dns_server() calls dns_getserver(index - 1, NULL).

Update lwipstack paths

Move lwipstack ...

- Public headers moved into mbed-os/connectivity/lwipstack/include/lwipstack folder
- Source moved into mbed-os/connectivity/lwipstack/source folder
- Internal lwip and lwip-sys libraries moved to source folder