Adding support for rendering 2D Point parameter type in filters settings generation
Since I'm working in adding support for OpenFX in MLT https://github.com/mltframework/mlt/compare/master...joinlaw:mlt:openfx I want to add support for point type in filters properties just like what natron do:
So the rectangle parameter looks like (from mlt filter_pillar_echo.yml):
```yml
- identifier: rect
title: Rectangle
description: >
Defines the rectangle of the area of interest.
Format is: "X Y W H".
X, Y, W, H are assumed to be pixel units unless they have the suffix '%'.
type: rect
default: "0 0 10% 10%"
readonly: no
mutable: yes
animation: yes
```
I suggest doing something like:
```yml
- identifier: position
title: Position
description: >
Defines the Position to draw
Format is: "X Y".
X, Y are assumed to be pixel units unless they have the suffix '%'.
type: double
widget: 2dpoint
default: "10% 10%"
...
```
I prefer using widget because 2D point could be double or integer (kOfxParamTypeInteger2D or kOfxParamTypeDouble2D)
Also discussed in the forum: https://discuss.kde.org/t/basic-openfx-support-development-log/39851/2
issue