Refactor symbol quoting into Symbol.quote_for_named_argument

[straight-shoota]

Every call to Symbol.needs_quotes_for_named_argument? in the compiler and stdlib is used in the same manner to decide whether to use the parameter directly or with inspect. All call sites look like this:

if Symbol.needs_quotes_for_named_argument?(x)
   x.inspect
else
  x
end

This PR extracts that common logic into a helper method Symbol.quote_for_named_argument.
Like .needs_quotes_for_named_argument?, it's nodoc.

All calls to Symbol.needs_quotes_for_named_argument? are replaced by Symbol.quote_for_named_argument, and the former is marked as deprecated.
It's a nodoc method, so this would not be absolutely necessary and we could just remove it right away. But it's still nice to keep it available for some time (at least till the next release).