Automated translation string extraction

To quickly create and update GUI localisation. Creating this took me longer than expected. It is at an experimental stage where this should not yet merged. I already stumbled on some problems that might need discussion:
* Pretty long translation keys to avoid duplicates: OK_BUTTON, CANCEL_BUTTON etc. get prefixed with the container/background widget label. I already tried line numbers, but those are variable later on therefore maybe confusing and they still generated duplicates like L9_TITLE_LABEL-Text. We can also try to eliminate the redundancy at one stage, however I tried solving it manually and that is too much manual labor.
* You will notice a lot of noise in https://github.com/Mailaender/OpenRA/commit/b083448ba4d8469000c26cdf25d151d45b9efda8 because for some reason we use `key: value` in rule YAML, but no space between `key:value` in chrome YAML. I can hack a workaround in here or we just auto-convert them stay in line with YamlWriter.