add symbol table and test file

lsp-server/test/test_symbol/test.tsf

@@ -0,0 +1,11 @@
+function f1(a: string; b: boolean = true): integer;
+begin
+end;
+
+function f2(a, b, c);overload;
+begin
+end;
+
+// var d := 1;
+// c := false;
+// f := fa();