Add graph type error diagnostics to the UI (#1535)

* Fontend input types

* Fix index of errors / types

* Bug fixes, styling improvements, and code review

* Improvements to the error box

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

website/other/bezier-rs-demos/public/style.css

@@ -112,6 +112,7 @@ body > h2 {
 
 svg text {
 	pointer-events: none;
+	-webkit-user-select: none;
 	user-select: none;
 }
 

website/sass/base.scss

@@ -280,6 +280,7 @@ pre {
 			font-size: 0.75em;
 			font-weight: bold;
 			font-style: italic;
+			-webkit-user-select: none;
 			user-select: none;
 			pointer-events: none;
 			position: fixed;
@@ -326,6 +327,7 @@ pre {
 				&:first-child {
 					padding-left: 20px;
 					padding-right: 10px;
+					-webkit-user-select: none;
 					user-select: none;
 					vertical-align: top;
 					text-align: right;