Blocks palette: tabs, options, drag insertion and -INSERT

Rebuild the Blocks palette with Current Drawing / Recent / Favorites /
Libraries tabs, wildcard filter, six views, insertion options, click and
drop insertion and a block context menu. INSERT opens the palette, the
new -INSERT runs on the command line, the ribbon Insert button becomes a
block gallery, and BLOCKMRULIST, BLOCKREDEFINEMODE, BLOCKNAVIGATE,
BLOCKSTATE, EXPLMODE and INSNAME are added.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/control/mod.rs

@@ -1340,6 +1340,7 @@ impl OpenCADStudio {
 mod actions;
 pub(crate) use actions::property_json;
 mod entities;
+pub(crate) use entities::erase_block_definition;
 #[cfg(not(target_arch = "wasm32"))]
 pub(crate) mod http_bridge;
 mod interactive;