app-layer-proto: speed up

app-layer-proto: speed up

AppLayer Proto detection code uses a mix of pattern search and
"probing parsers". The pattern search validates potential matches
using a single pattern search algo. The code was using SpmSearch
for this, but this made it inefficient as it builds a BoyerMoore
context for each search. This lead to significant memory pressure,
especially on high speed/bandwidth boxes.

This patch switches the search calls to BoyerMoore and BoyerMoore-
Nocase directly. This can be done as the ctx' were available already.