[processing] Range widget (partial)fix for modeler. Fixes #19785

[luipir]

Description

This PR allow to add in modeler and without error, scripts or algs using QgsProcessingParameterRange. In this moment there is no complete integration e.g. the range parameter can't be used as input/output in the modeler, but it's a start point allowing to add algorithm without modifiy them to QgsProcessingParameterNumber as workaround to be used in modeler.
Added also tests for the RangePanel.

fix promoted inside GeoMove [1] project for Cartolab [2] (A Coruña university)

[1] http://cartolab.udc.es/geomove/
[2] http://cartolab.udc.es

Checklist

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• New unit tests have been added for core changes
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[luipir]

discussion started at https://issues.qgis.org/issues/19785 can follow here!