detect-parse: improve common parser

detect-parse: improve common parser

In preparation of turning input to keyword parsers to const add
options to the common rule parser to enforce and strip double
quotes and parse negation support.

At registration, the keyword can register 3 extra flags:

    SIGMATCH_QUOTES_MANDATORY: value to keyword must be quoted

    SIGMATCH_QUOTES_OPTIONAL: value to keyword may be quoted

    SIGMATCH_HANDLE_NEGATION: leading ! is parsed

In all cases leading spaces are removed. If the 'quote' flags are
set, the quotes are removed from the input as well.