Settings: add parameter to Pro Parser list

Steps to reproduce the problem:

1. go to Settings > Pro Parser to add a default PRO-parameter

Expected result: a list of all default SNOWPACK output parameter

Actual result: empty field (see attached)

In a first step all default parameters can be added in lib/parsers/pro.js (by WSL/SLF). A flag could be added to allow removing unwanted parameters as having too many parameters to parse may slow down performance.