Options formatted as a list of comma-separated key-value pairs may have
values that contain leading and trailing whitespace characters. For
example, the `listchars` option has a default value of
`"tab:> ,trail:-,nbsp:+"`. When converting this value to a lua table,
leading and trailing whitespace should not be trimmed.
Co-authored-by: Robert Hrusecky <robert.hrusecky@utexas.edu>