Redesign "Add" dialog in "Network Configuration" section

[alinefm]

It was firstly reported at kimchi-project/ginger#308 but it is a Ginger s390x functionality.

As described at kimchi-project/ginger#300, the "Add" should be a single button instead of a combo box as most of the information collect for BOND and VLAN are the same. So we don't need to maintain different dialog for each one.

Said that, my suggestion is: once "Add" button is selected a new dialog is open as it is done today with 3 tabs: General, IPv4 Settings and IPv6 Settings.
(The Advanced tab will be moved as a collapse/expand area into General tab)

Current General tab for BOND interface:

Current General tab for VLAN interface:

My proposal to the General tab is described in the mockup below.

Interface Name: | <input box> |
Interface type: | <combo box with BOND and VLAN options> |
[ ] Connect Automatically

When BOND option is selected, a new content will be displayed (similar to what we have when adding a new storage pool in Kimchi).

For BOND:

Mode: | <combo box with options> |
BOND Members: | <multiple selector combo box listing the host interfaces |

+ Advanced
Link monitoring: | <combo box> |
Monitoring interval: | <integer input box> |
Link up delay: | <integer input box> |
Link down delay: | <integer input box> |

PS. The multiple selector combo box is the same used to create a VEPA network in Kimchi.

For VLAN:

Parent interface: | <combo box> |
VLAN ID: | <input box> |
MTU: | <input box> |

---

Current "IPv4 Settings" tab:

My proposal to IPv4 Settings tab is described in the mockup below.

IPv4: | <toggle on/off widget> |

ONLY when IPv4 is set to ON the fields described below is shown:

Method: | <combo box with DHCP and Manual options> |

When DHCP is selected, display the following fields:

+ DNS
|                  <add icon> New |
|                                 |

+ Routes
[ ] Enable IPv4 default route

| Address | Netmask | Gateway | Metric |
|                       <add icon> New |
|                                      |

When "New" button is selected, a input box is added to the table so user can add the DNS value.
In case of Route, we need a row table input box, so user will enter values for address, netmask, gateway and metric.

When "Manual" is selected, the DNS and Routes areas shown on DHCP is also displayed in addition to one new section, described below:

+ IP Address
| Address | Netmask | Gateway |
|              <add icon> New |
|                             |

When "New" button is selected, we need a row table input box, so user will enter values for address, netmask and gateway. The same used for Route above.

The "IPv6 Settings" tab will look the same as "IPv4 Settings". With the same fields and behavior but to collect IPv6 information.