Split DetectHelperKeywordRegister into 2 functions, one for acquiring
a new keyword ID, and another to perform the registration.
This makes it easier to do the traditional C keyword initialization
with a dynamic ID.
git grep -A 1 -w InspectionBufferSetup shows many cases of the following
call patterns:
- InspectionBufferSetup
- InspectionBufferApplyTransforms
Refactor the implementations of those functions into
InspectionBufferSetupAndApplyTransforms to reduce function call count.
Issue: 2290 (related to changed for this issue)