[libkwineffects] Add support for shaders in AnimationEffect

The animate and set calls are extended for an optional GLShader* to
allow specifying a custom shader to use during the animation.

To properly support rendering a complete window in the effect the
AnimationEffect gets based on the DeformEffect. If a shader is used
during the animation the window gets redirected.

For the animation with shaders two new enum values are added to the
AnimationType enum:
 * Shader
 * ShaderUniform

The Shader animation type is for specifying that the animation uses a
shader. During the animation a uniform "animationProgress" is set on the
shader.

The ShaderUniform animation type behaves exactly like the Shader type,
but also animates a user provided uniform. The meta data of the
animation is interpreted as a uniform location for a float uniform and
during the animation this uniform is updated with the interpolated
animation data.