Add support to take action based on string format specifier.
If string template is '%d' and value type is double, do safe
conversion to int from double.
indicator_format_set/get & indicator_format_function_set are
now legacy APIs.
indicator format can be set by using generic Ui.Format function
e.g.
efl_ui_format_string_set(efl_part(sliderObj, "indicator"), "1.0%f");
This generic format_string would be used in slider,progressbar
and other widgets.This default function handles INT
and DOUBLE eina value types for now.
Ref T6204