Fix non-unique module handler identifiers

[J-N-K]

Fixes #3505

The cause is the naming of the module handlers. Internally the BaseModuleHandlerFactory stores the modules in a Map where the key is ruleUid+moduleId.

Textual defined rules have ruleUid that consists of the filename, a dash and a number that denotes the position of the rule in the file, so in a file foo.rules, the first rule gets a foo-1, the 11th gets foo-11. Within a rule, the modules are numbered from 0 to n. So the if the first rule has 10 triggers, the last module handler is stored with a key foo-110. When the 11th rule is added and has a trigger of the same type as first trigger, the BaseModuleHandlerFactory generates the same key and returns the already created handler for 10th trigger of rule 1 instead creating a new handler.

This PR changes the key to <ruleUid>$<moduleId>. This should be safe because $ is not an allowed character for the module id and collisions are prevented.

[kaikreuzer]

Thanks, interesting effect.