feat(compiler): support a non-null postfix assert (#16672)

Template expressions can now use a post-fix `!` operator
that asserts the target of the operator is not null. This is
similar to the TypeScript non-null assert operator. Expressions
generated in factories will be generated with the non-null assert
operator.

Closes: #10855

packages/compiler/src/output/output_interpreter.ts

@@ -233,6 +233,9 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
   visitNotExpr(ast: o.NotExpr, ctx: _ExecutionContext): any {
     return !ast.condition.visitExpression(this, ctx);
   }
+  visitAssertNotNullExpr(ast: o.AssertNotNull, ctx: _ExecutionContext): any {
+    return ast.condition.visitExpression(this, ctx);
+  }
   visitCastExpr(ast: o.CastExpr, ctx: _ExecutionContext): any {
     return ast.value.visitExpression(this, ctx);
   }