NewTransformerBackendConfigHandler returns http request handler to handle all backend config requests by transformer.

WithConfigBackendURL lets transformer use custom backend config server for transformations WithConfigBackendURL should not be used with WithUserTransformations option.

WithConnectionToHostEnabled lets transformer container connect with the host machine i.e.

WithUserTransformations will mock BE config to set transformation for given transformation versionID to transformation function map - events with transformationVersionID not present in map will not be transformed and transformer will return 404 for those requests - WithUserTransformations should not be used with WithConfigBackendURL option - only javascript transformation functions are supported e.g.