feat(lsp): interface dispatch in call hierarchy (0.11)

Index interface methods and extend Type for Trait relations so call
hierarchy can show implementors as outgoing targets and .Method call
sites as incoming.

- interface I { func M } + extend T for I tracking
- prepare/outgoing/incoming with data Iface#Method
- smoke_lsp_iface_hierarchy (Drawable.Draw ↔ Circle / Render)

tools/smoke_lsp_method_hierarchy.sh

@@ -58,7 +58,7 @@ URI="file://$TMP/Main.bux"
   rpc '{"jsonrpc":"2.0","method":"exit","params":null}'
 } | "$LSP" 2>/dev/null | tr '\r' '\n' > "$TMP/out.txt"
 
-if ! grep -qE '0\.(9|10)\.0' "$TMP/out.txt"; then
+if ! grep -qE '0\.(9|10|11)\.0' "$TMP/out.txt"; then
   echo "WARN: unexpected bux-lsp version"
 fi