Details:
- Consolidated the two blocked variants for packm into a single
implementation (packm_blk_var1) and removed the other variant.
- Updated all induced method _cntl_init() functions in frame/cntl/ind/
to use the new blocked variant 1.
- Defined two new macros, bli_is_ind_packed() and bli_is_nat_packed(),
to detect pack_t schemas for induced methods and native execution,
respectively.