[FIX] component: strict check of deep argument truth value

With this commit, we make sure that the `render` method was explicitely
called with the deep === true argument, instead of assuming that it is a
boolean.  This prevents errors when some unrelated value is given to the
render method. This could happen in some cases, such as

useBus(someBus, 'someevent', this.render)

In that case, the `useBus` code would simply call the this.render with a
customevent, which would be considered truthy before, and not anymore

tests/components/__snapshots__/rendering.test.ts.snap

@@ -127,6 +127,30 @@ exports[`rendering semantics props are reactive 2`] = `
 }"
 `;
 
+exports[`rendering semantics render need a boolean = true to be 'deep' 1`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = text(ctx['state'].value);
+    const b3 = component(\`Child\`, {}, key + \`__1\`, node, ctx);
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`rendering semantics render need a boolean = true to be 'deep' 2`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    return text(\`child\`);
+  }
+}"
+`;
+
 exports[`rendering semantics render with deep=true followed by render with deep=false work as expected 1`] = `
 "function anonymous(bdom, helpers
 ) {