white-space characters in variable substitutions

[kadel]

Trailing and leading spaces in variables should not matter.

Currently If I have something like this:

schemaVersion: 2.1.0
metadata:
  name: test
variables:
  VARIABLE_TEST: bar
components:
  - name: test
      env:
        - name: "FOO"
          value: "{{ VALUE_TEST }}"

it is invalid due to spaces before }} and after {{.
It would be good if the leading and trailing whitespace were ignored.