Add filter by --tags option to 'openstack network list' command

[Badhmapriya Boopalan]

OSC's 'network list' can be enhanced to filter networks by Tag

Scenario :
Create a network. Add a tag named 'blue' via Neutron client.
(Add/Update/Remove Tags is not currently supported in OSC & a Blueprint is in order to implement it)

stack@openstack-vm:/home/priya_openstack/devstack$ openstack network show 11f5f13c-a65c-4b3e-9059-494f71a83861
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | |
| created_at | 2016-12-01T14:39:23Z |
| description | |
| id | 11f5f13c-a65c-4b3e-9059-494f71a83861 |
| ipv4_address_scope | None |
| ipv6_address_scope | None |
| mtu | 1450 |
| name | MyLocalNetwork |
| port_security_enabled | True |
| project_id | a77594351c5a47edba959addd54f8609 |
| provider:network_type | vxlan |
| provider:physical_network | None |
| provider:segmentation_id | 77 |
| revision_number | 3 |
| router:external | Internal |
| shared | False |
| status | ACTIVE |
| subnets | |
| tags | [u'blue'] |
| updated_at | 2016-12-01T14:39:23Z |
+---------------------------+--------------------------------------+

Note :
1. 'tag' is displayed as [u'blue'] instead of 'blue'. Looks like there is a seperate bug inplace to address this issue
2. #1578819 Add network list filtering options - This bug had added filtering options to network list, excluding tags.

Solution : Enhance the feature of filtering list by Tag. (ex : openstack network show xxx_networkId --tags tag_name)

[Badhmapriya Boopalan (priyaboopalan)]

I'm planning to work on this bug Nitesh