ZegoEffectsLongChinParam constructor Null safety

1. zego_effects_plugin
2. zego_effects_defines
3. ZegoEffectsLongChinParam
4. ZegoEffectsLongChinParam constructor

ZegoEffectsLongChinParam class

1. Constructors
2. ZegoEffectsLongChinParam
3. Properties
4. intensity