Create a sniff to ensure `update_option` sets `autoload` explicitly

[moorscode]

As the autoload setting has been added in a later state, the argument is not required.
Though this is a setting that should be set explicitly, as it impacts performance and memory.

[jrfnl]

As the autoload setting has been added in a later state, the argument is not required.

Not sure if that's the reason. The autoload setting has always been optional for add_option() and AFAIK, has been available since the beginning, so I suspect it's more a consistency thing.

Implementation notes:

• This should be checked for both update_option() as well as add_option().
• WPCS contains an abstract function parameter sniff which can (should) be used as a basis.

Note: using update_option() you can change the autoload which was added when the option was created, but only when changing the value at the same time.
So if update_option() is used for adding new options: great.
If update_option() is used to actually update an existing option, it a) may not have any effect if the option already exists and b) is basically superfluous.

So some careful thought is needed about what should actually be checked for and whether this should be a warning or an error.