feat(lsp): warn on undeclared block templates and addresses

Add diagnostics that warn when a literal NX command argument names a block
template or address that no loaded .def file declares (diagnostic codes
unknown-block-template and unknown-address). Names computed at runtime
(e.g. $var or "CYCLE_$x") are not checked, and kinds whose .def file is
not loaded are skipped.

The server now recomputes and refreshes diagnostics when .def documents
change (clears cached diagnostics and requests a workspace diagnostic
refresh if the client supports it). Tests cover positive, negative and
invalidated-cache cases.

CHANGELOG.md

@@ -12,6 +12,7 @@ Versions correspond to the Git tags of this repository.
 - Find References and Rename for block templates and addresses across Tcl and `.def` files, including addresses used inside block templates
 - Go to Definition, hover, references, and rename also work inside `.def` files
 - Hover and Go to Definition also recognize block template and address names that reach an NX command through a local variable (`set`, `lappend`, `list`, `foreach`) or through the parameter of a custom proc such as `LIB_SPF_call_cycle "absolute_mode"`, including nested wrapper procs; same-named strings without such a path are not recognized, and these derived names are not renamed
+- Warning for block template and address names in NX commands (`MOM_do_template stedy_rest`) that no loaded `.def` file declares; names built at runtime (`$var`, `"CYCLE_$x"`) are not checked, and the warnings update when a `.def` file changes
 - Completion items for block templates and addresses (`BLOCK_LIST`, `ADDR_LIST`, `MOM_do_template`, ...) show the same preview as the hover
 
 ### Documentation