Place looking_glass in the broker plugins file if -c dbg is set

in bazel

(cherry picked from commit 55d3d22)
(cherry picked from commit 1674707)
(cherry picked from commit fbb4101)

Author: HoloRin

BUILD.bazel

@@ -135,7 +135,10 @@ plt(
 
 PLUGINS = all_plugins(
     rabbitmq_workspace = "",
-)
+) + select({
+    "@rules_erlang//:debug_build": ["@looking_glass//:erlang_app"],
+    "//conditions:default": [],
+})
 
 rabbitmq_home(
     name = "broker-home",