Allow suffixes to be added to gazetteer field names

[geographika]

By default field names are expected to be minX3857 etc.
This update allows different suffixes to be added so fields such as minX2157 can be used, using a new fieldNameSuffixconfig setting onCpsiMapview.view.combo.Gazetteer`:

Example:

{
    xtype: 'cmv_gazetteer_combo',
    url: '/gazetteer/',
    srs: 'EPSG:2157', // also set the project to use for the extents
    fieldNameSuffix: '2157',
    proxyRootProperty: 'data',
    displayValueMapping: 'name',
    emptyText: 'Townland...'
}

Ext.create('CpsiMapview.view.combo.Gazetteer', { fieldNameSuffix: '2157' });