Update Legacy Magic Keycodes

[noroadsleft]

Description

• change LAG_SWP to AG_LSWP
• change LAG_NRM to AG_LNRM
• change RAG_SWP to AG_RSWP
• change RAG_NRM to AG_RNRM
• change GUI_ON to GU_ON
• change GUI_OFF to GU_OFF
• change LCG_SWP to CG_LSWP
• change LCG_NRM to CG_LNRM
• change RCG_SWP to CG_RSWP
• change RCG_NRM to CG_RNRM

Fixes #1352.