A KWin::EffectPluginFactory is introduced which provides a specialized
create method and methods for the supported and enabledByDefault checks.
A set of KWIN_EFFECT_FACTORY macros are added which create a subclass
of this EffectPluginFactory following the approach from the
KPluginFactory macros. The macros only support json metadata thus the
QPluginTrader needs to be used.
The KWIN_EFFECT macros are removed as they are no longer needed.
KWin Core's loader is not yet adjusted to this change. This is a
preparation step for introducing a PluginEffectLoader.
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