IDS: Redesign backend for used provider rulesfiles.
The selected rulesfiles of a provider now will be written to an own
provider exclusive yaml file, which will be included dynamically when
the provider is enabled or not.
This allows very easy handling to enable or disable a provider, in this
case the file which keeps the enabled providers rulesets only needs to
be included in the main file or even not.
Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>