Modify the design of TopoModif

[Diego635]

We need to implement rescaling in the tool.
This could be 3 options:

1. Modification with formula
   Here we should ask for:

• Bounding values (bounding min / bounding max)
• Formula

2. Heightening / flattening
   Here we should ask for:

• Final maximum (the user chooses the highest value of the resulting topography)
  The minimum value should be taken automatically from the raster. And we shouldn't give the possibility to choose a minimum here, it's to confusing.

3. Rescaling
   Here we should be asking for:

• Bounding values (bounding min / bounding max)
  --> If there is an empty field here, the original min and max values from the raster should be taken.
• Final max and final min (the desired values for the resulting topography)

[Diego635]

This is partially solved. The points 2. and 3. need to be revised (perhaps no need to implement them?)

[Diego635]

When the option to take the min/max values or the formula from the attributes is selected, the comboboxes should replace the spinboxes. This will make the interface look more clear.

[Diego635]

The tool has become too complicated. It works but the interface could be more user-friendly. A series of pop-up windows (Installation wizard with next buttons), similar to a software installation, might work better.
see #129
Possible tree:
Input > Formula or MinMax modification > depending in the modification type chosen, corresponding settings > Output and log.

First specify data types that the user has and then merge masks

[jaminzoda]

To keep it consistent with the overall dialogs design and to implement a single base dialog that is used by all the algorithms the TopoModify dialog is simplified instead of providing parameters on separate pages of a wizard. Fixed in 0300073