fix(parser): add support for .udt and .db file parsing and goto declaration

- extract_variables: Parse STRUCT fields in TYPE sections for .udt files
- extract_types: Handle quoted type names and multiple type definitions
- declaration handler: Extract quoted type names for goto declaration
- Add filetype detection for .udt and .db files in nvim config

src/main.lua

@@ -558,7 +558,7 @@ function handlers.textDocument_declaration(params)
 		local var_type = doc.variables[word].data_type
 		if var_type then
 			var_type = var_type:gsub("%s*;.*$", ""):gsub("%s*:=.*$", ""):gsub("^%s+", ""):gsub("%s+$", "")
-			local type_name = var_type:match("([%w_]+)")
+			local type_name = var_type:match('"([^"]+)"') or var_type:match("([%w_]+)")
 			if type_name and type_name ~= word then
 				table.insert(search_names, type_name)
 			end