Add support for RETRO_ENVIRONMENT_SET_CONTENT_INFO_OVERRIDE API extension - enables soft patching of non-CD content

[jdgleaver]

This PR adds support for the new libretro RETRO_ENVIRONMENT_SET_CONTENT_INFO_OVERRIDE API extension introduced here: libretro/RetroArch#12473

Using this extension, the core's need_fullpath requirement is suspended for content of the following file types: .gen, .smd, .md, .32x, .sms

As a result:

• Frontend softpatching is now supported for these file types
• When loading these file types from compressed archives, it is no longer necessary for the frontend to extract the content to a temporary file on-disk