This PR create a corresponding entry in the $globals.config map for every $globals.ENV.* value that where previously accessed throughout the template, so those global values can be displayed by the debug endpoint from #2525.

The PR also try to cut down on some non idiomatic / hard to read stuff :

• expressions like (foo (bar (buzz (qux "something")))) , replaced by qux "something" | buzz | bar | foo.
• use of coalesce / or to get a default value to a possibly null or empty one (coalesce "nullable" "defaultValue"), replaced by "nullable" | default "defaultValue"

note: the boolean values in $globals.config that are used later in the template as a default global value to per-vhost one are currently strings rather than real booleans, and displayed as such in the debug endpoint. This is to avoid an additional if / else / end for each of those values when using them as fallback default.