obs-scripting: Add obs_properties_add_button2

[exeldro]

Description

Add obs_properties_add_button2 to scripting

Motivation and Context

obs_properties_add_button is deprecated, so the documentation indicates to use obs_properties_add_button2, but that does not exist yet in scripting

How Has This Been Tested?

On windows 11 by running the scripts that are modified

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code is not on the master branch.
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[sebastian-s-beckmann]

The scripting-custom obs_properties_add_button already behaves like libobs' obs_properties_add_button2 (in fact, it uses the libobs v2 function internally, which was originally introduced for exactly that scripting function), so there is no need for this change.
If there is any confusion about this, maybe the documentation needs some kind of update.

[exeldro]

Updating the docs might also help, but than we still need to not auto generate scripting functions for obs_properties_add_button2