fixes #1027; disallow templates to use ambiguous identifiers (#20631)

* test qualifiedLookUp in templates

* check later

* add testcase

* add 4errormsg

* Update tests/template/m1027a.nim

Co-authored-by: Clay Sweetser <Varriount@users.noreply.github.com>

* Update tests/template/m1027b.nim

Co-authored-by: Clay Sweetser <Varriount@users.noreply.github.com>

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
Co-authored-by: Clay Sweetser <Varriount@users.noreply.github.com>

compiler/semtempl.nim

@@ -376,6 +376,8 @@ proc semTemplBody(c: var TemplCtx, n: PNode): PNode =
         result = newSymNode(s, n.info)
         onUse(n.info, s)
       else:
+        if s.kind in {skType, skVar, skLet, skConst}:
+          discard qualifiedLookUp(c.c, n, {checkAmbiguity, checkModule})
         result = semTemplSymbol(c.c, n, s, c.noGenSym > 0)
   of nkBind:
     result = semTemplBody(c, n[0])