Inconsistent naming of alarms between modules

[henningwold]

Two of the alarm modules uses two input variables to decide the name, while the last (alb) only uses one. It would probably be a good idea to standardize on either-or of the methods used. Personally I would probably recommend name_prefix (maybe even rename it to naming_prefix - at least write a good description of what it actually does in the variables file).

This is especially problematic in the API Gateway module, as the prefab modules for API Gateway uses both name_prefix and application_name to actually name the resource. Thus to actually get the module to pick up the correct metrics, you have to send in api_name="${var.name_prefix}-${var.application_name}" to the API Gateway alarm module (at least as of v0.1.0 of the api gateway module). This, of course, makes the actual name of the alarm something like "${var.name_prefix}-${var.name_prefix}-${var.application_name}" which, suffice to say, is fairly silly.