feat(modify): TXTEXP turns text into its character outlines

TXTEXP replaces each selected TEXT and MTEXT with one polyline per
glyph contour, on the text's layer and with its properties: a
lightweight polyline for flat text, a 3D polyline for tilted text.
The outlines come from the same glyph tessellation the text renders
with, so stroke fonts give their strokes and outline fonts their
closed contours.

Refs D#1665

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/locale_catalog.rs

@@ -3697,6 +3697,7 @@ pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static
         "Width factor" => Some(("common", "width-factor-sentence-case")),
         "Width: %{value}" => Some(("ui", "width-value")),
         "Window" => Some(("common", "window")),
+        "TXTEXP: no text selected." => Some(("common", "txtexp-no-text-selected")),
         "Windows desktop" => Some(("styles", "windows-desktop")),
         "Wipeout" => Some(("common", "wipeout")),
         "Wireframe" => Some(("common", "wireframe")),