[Print] Ability to print image legend with an appropriate scale

[dsuren1]

Description

Provide the ability to print legend image with the configured scale of the layer in the layer options (Display -> Legends).

Currently the MS uses the iconSize of the legend options in print tool to set width and height of the legend

Example: with internal layer

iconSize: 20	iconSize: 40

The print tool's Legend Options will be modified to have two fields called Width and Height replacing the Icon Size field along with a new checkbox field called Override icon size. These new fields will hold the current default size of 24px.
This override option will allow user to override legend's configured scale (width and height) set for the layer in the layer options and when more than one layer is present, this option will be applied for the all the applicable layers.

By default, this option will be unchecked, meaning the legend's width and height configured in layer will be used per layer

Reason: Print tool has a common option for all the layers selected for printing and cannot be made available per layer, hence a common option will be used for all layer when user prefer to override the icon size

Other useful information

Ref: georchestra/mapstore2-georchestra#682

[dsuren1]

Updated:

The legend options will have checkbox Override icon size, this will override legend's width and height set for the layer in the layer options and will be applied for the all the applicable layers. By default, this option will be unchecked, meaning the legend's width and height configured in layer will be used.

Reason: Print tool has a common option for all the layers selected for printing and cannot be made available per layer in the print tool, hence a common option will be used for all layer when user prefer to override the icon size