triggers: refactor: let match_result_t be a struct with fire and timing variables

Mapping of previous and revised match_result_t data type:
-------------------------------------------
   Previous                 Revised
MATCH_NONE               fire=false (don't care timing)
MATCH_MATCH_FIRE_BEFORE  fire=true,timing=TIMING_BEFORE
MATCH_MATCH_FIRE_AFTER   fire=true,timing=TIMING_AFTER