cml_node | coordinates support

[tvarohohlavy]

Implements usage of X and Y coordinates for nodes which makes it possible to place nodes at specific coordinates or update placement of existing nodes.

The behavior implemented is only applicable for present state as for others it does not have a meaning.
Both below options apply for either X or Y coordinate separately:
a) if defined: make sure the node coordinate is as provided so update of coordinate will happen if its not as provided
b) if not defined: no action related to specific coordinate

In case X or Y is not defined during node creation the default is 0. When such node already exists coordinates are not checked if not defined.

Partial fix for issue: #44

Examples:

  - name: Create Nodes
    cisco.cml.cml_node:
      name: "{{ item.hostname }}"
      state: present
      node_definition: "{{ item.node_definition | default(omit) }}"
      x: "{{ item.x | default(omit) }}"
      y: "{{ item.y | default(omit) }}"
    loop:
      # new node
      - hostname: switch01 # new node is created and will be placed at [0,-240]
        node_definition: unmanaged_switch
        x: 0
        y: -240
      - hostname: switch02 # new node is created and will be placed at [0,-120]
        node_definition: unmanaged_switch
        y: -120
      - hostname: switch03 # new node is created and will be placed at [0,0] - same as previous behavior
        node_definition: unmanaged_switch
      # existing node
      - hostname: switch01 # node is moved from [0,-240] to [100,-120]
        x: 100
        y: -120
      - hostname: switch01 # node is moved from [100,-120] to [100,-130]
        y: -130
      - hostname: switch01 # node is moved from [100,-130] to [0,-130]
        x: 0
        y: -130