Allow sketch text fields to be ui/cli params

[kneitinger]

The #[sketch] attribute macro in sketch_derive will currently autogenerate clap/custom code for setting integral, floating point and boolean values. A lot of my recent work uses text, and having that be a cli option or UI setting would be great.

The general infrastructure for this is already in place; the main hurdle is just handling lifetimes/ownership with aggregate datatypes.

For cli settings, quotations handle any whitespace/newlines. For UI, this setting should likely be a multiline text box.