[FIX] compiler: multiple modifiers on t-custom

Since [1] it's possible to have a custom directive, this directive only
supported one modifier. This commit, add the support to have multiple
modifiers on a t-custom directive.

[1] : https://github.com/odoo/owl/commit/7e687234bf40bdcf5e6598401d8604d66b14ad32

src/common/types.ts

@@ -1,4 +1,4 @@
 export type customDirectives = Record<
   string,
-  (node: Element, value: string, modifier?: string) => void
+  (node: Element, value: string, modifier: string[]) => void
 >;

src/compiler/parser.ts

@@ -299,10 +299,10 @@ function parseTCustom(node: Element, ctx: ParsingContext): AST | null {
         throw new OwlError(`Custom directive "${directiveName}" is not defined`);
       }
       const value = node.getAttribute(attr)!;
-      const modifier = attr.split(".").length > 1 ? attr.split(".")[1] : undefined;
+      const modifiers = attr.split(".").slice(1);
       node.removeAttribute(attr);
       try {
-        customDirective(node, value, modifier);
+        customDirective(node, value, modifiers);
       } catch (error) {
         throw new OwlError(
           `Custom directive "${directiveName}" throw the following error: ${error}`