DB/SAI: Clear param2 for Remove Aura

Clear exististing data in param2 for sai entries using smart_action 28 as these param was previously unused but some lines of sai still had this param > 0
Core/SAI: Allow dropping a specific amount of aura charges using SMART_ACTION_REMOVEAURASFROMSPELL (action_param2).

(cherry picked from commit ed4feec276bd395715c23c58b74a6dae4198039b)
Merge pull request #13432 from bloerwald/fix_compiler_detection_on_unix

cmake: platform: also detect clang by C_COMPILER_ID: C_COMPILER may vary
(cherry picked from commit 774e22ec4a8859664ace0a532c2ab4ae220e5cc9)