* Refactor common network shared and platform specific code into package (part-1)
As per proposal #76 refactor common network shared and platform specific
code into sub-package.
https://github.com/ansible/proposals/issues/76
* ansible.module_utils.network.common - command shared functions
* ansible.module_utils.network.{{ platform }} - where platform is platform specific shared functions
* Fix review comments
* Fix review comments
* Code cleanup
Removed 'add' method from CustomNetworkConfig. It is identical
to the one inherited from NetworkConfig
* Removed unused CustomNetworkConfig import
* Replaced
```
def get_existing(module, args):
existing = {}
netcfg = get_config(module)
config = netcfg.get_section(parents)
```
with
```
netcfg = CustomNetworkConfig(indent=2, contents=get_config(module))
```
get_config returns a string, not an object in 2.3.
* Removed non-functioning get_object method in CustomNetworkConfig in favor of the
inherited method.
Added child_objs property so that expand_selection would work. The original
verion never worked correctly as it compared NetworkConfig obj's and str's.
* Removed ShellError method in favor or new load_config method.
* Removed ShellError method in favor or new load_config method.
fixes#20260
* nxos requires a "no" statement to change mcase group. Corrected.
Corrected changed logic.
* Corrected deleted CustomNetworkConfig import
Changes to the metadata format were approved here:
https://github.com/ansible/proposals/issues/54
* Update documentation to the new metadata format
* Changes to metadata-tool to account for new metadata
* Add GPL license header
* Add upgrade subcommand to upgrade metadata version
* Change default metadata to the new format
* Fix exclusion of non-modules from the metadata report
* Fix ansible-doc for new module metadata
* Exclude metadata version from ansible-doc output
* Fix website docs generation for the new metadata
* Update metadata schema in valiate-modules test
* Update the metadata in all modules to the new version
This completes the refactor of the nxos modules to use the persistent
connection. It also updates all of the nxos modules to use the
new connection module and preserves use of nxapi as well.