Prefix outputs with * within the engine.

Prefix output strings with * so they are always permissive in the
engine.

In falco outputs, which adds its own prefix, remove any leading * before
adding the custom prefix.

userspace/engine/lua/rule_loader.lua

@@ -436,7 +436,10 @@ function on_event(evt_, rule_id)
       rule_output_counts.by_name[rule.rule] = rule_output_counts.by_name[rule.rule] + 1
    end
 
-   return rule.rule, rule.priority, rule.output
+   -- Prefix output with '*' so formatting is permissive
+   output = "*"..rule.output
+
+   return rule.rule, rule.priority, output
 end
 
 function print_stats()

userspace/falco/lua/output.lua

@@ -76,6 +76,13 @@ end
 
 function output_event(event, rule, priority, format)
    local level = level_of(priority)
+
+   -- If format starts with a *, remove it, as we're adding our own
+   -- prefix here.
+   if format:sub(1,1) == "*" then
+      format = format:sub(2)
+   end
+
    format = "*%evt.time: "..levels[level+1].." "..format
    if formatters[rule] == nil then
       formatter = formats.formatter(format)