Simplified how sheet names are matched against "sheet" query arg

Author: Mitch Davis

src/kicanvas/elements/kicanvas-shell.ts

@@ -148,9 +148,7 @@ class KiCanvasShellElement extends KCUIElement {
                         target_page = page;
                         break;
                     }
-                    const match = page.project_path.match(/^([^:]+)/)!; // If there's a colon, only take the part before it
-                    const filenamePart = match[1]
-                    if (filenamePart == sheet_param) {
+                    if (page.filename === sheet_param) {
                         target_page = page;
                         break;
                     }