Fix property read syntax to supported by more tools

[VincentLanglet]

Hi,

This PR is kinda similar to https://github.com/gocardless/gocardless-pro-php/pull/186 in the idea

The issue I encountered is that the syntax

@property-read $foo

is not a valid one for lot of PHPtool, and

@property-read TYPE $foo

should be preferred instead.

Since none of the property are typed in this lib,

@property-read mixed $foo

does the job.

As an example,

• all the example by phpdocumentor have typed https://docs.phpdoc.org/3.0/guide/references/phpdoc/tags/property.html
• PHPStan fails on https://phpstan.org/r/2534dcd1-fb4e-47af-80f2-1d2f896ec6aa but not on https://phpstan.org/r/6da7b153-e2c3-46f9-a5d4-7f241436e7b7

In the same way, all this files are generated by crank, so I cannot contribute to them. Is there a way to have acces to crank or that someone move this fix to the crank library @barrucadu @Nimisoere @opsz2 @NickLewry ?

Thanks