Implement ZED Mini support

[Xovval]

This is currently not possible because of the following reasons:

OpenXR:

• ZED Plugin doesn't support OpenXR yet and needs SteamVR to run on SteamVR devices (https://github.com/stereolabs/zed-unity/issues/233#issue-1184997310)
• It could be possible to modify the plugin but this is not recommended for longevity reasons

SteamVR:

• When using BiRP, the SteamVR player doesn't want to be created on Start(), which makes a variable switch between VR/AR impossible
• HDRP clashes (when using the ZED Plugin, the scene has problems with the directional light - changing the material of the "Frame" objects to Unlit does fix the issue in the preview but has a more darker result in the HMD). Note that if this issue wouldn't exist, this workaround would work.
• The Varjo SDK does only support basic, legacy AR with SteamVR currently (if there aren't any bugs)

[Xovval]

Created an issue in the community forum regarding HDRP: https://community.stereolabs.com/t/unity-zed-plugin-hdrp-issues/1125