Newly-created apps cannot add custom action syntax

[jessecarterMOOSE]

Bug Description

The registerSyntax macro (and possibly others) use the "syntax" variable name, but the registerAll() function in a new stork-created app's constructor (src/base/<AppName>App.C) uses the local variable "s". Workaround for now is to add auto & syntax = s; before registering.

@GiudGiud From discussion in #28826

Steps to Reproduce

Create a new app from stork.sh and add custom syntax like registerSyntax("MyAction", "SyntaxString");

Impact

More of an annoyance since there is a workaround

[Optional] Diagnostics

No response