st/nine: Reimplement nine_context_apply_stateblock
st/nine: Reimplement nine_context_apply_stateblock

The new version uses nine_context functions instead of
applying the changes directly to nine_context.
This will enable it to work with CSMT.

v2: Fix nine_context_light_enable_stateblock
The memcpy arguments were wrong, and the state
wasn't set dirty.

Signed-off-by: Axel Davy <2b6ef604b998fb81662f85c329e4fc020eae8e5d@ens.fr>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler