* fix static combo chart crashes when viz settings are invalid

* spec

* Rename "Line style" to "Line shape"

* Add "line.style" viz setting

* Add "line.size" viz setting

* Apply new viz settings in line/area charts

* Clean up `ChartSettings` test suite

* Fix default values not applied

* Add visual test

* Add E2E test

* Rework default values

* Use constant S/M/L values for "line.size" setting

Co-authored-by: Emmad Usmani <emmadusmani@berkeley.edu>
Co-authored-by: Adam James <adam.vermeer2@gmail.com>
Co-authored-by: Mark Bastian <markbastian@gmail.com>
Co-authored-by: Jesse Devaney <22608765+JesseSDevaney@users.noreply.github.com>
Co-authored-by: Anton Kulyk <kuliks.anton@gmail.com>