Scheme registration: Avoid admin privileges

[iLLiCiTiT]

Please describe the feature you have in mind and explain what the current shortcomings are?

We require admin privileges to register ayon-launcher scheme, but it looks like it might not be required.

How would you imagine the implementation of the feature?

This needs validation but it looks like we create scheme handler in HKEY_CURRENT_USER\SOFTWARE\Classes\ayon-launcher. And it should also override the HKEY_CLASSES_ROOT\ayon-launcher handler.

Steps would be:

• Validate if ayon-launcher is set in HKEY_CURRENT_USER\SOFTWARE\Classes\ayon-launcher.
• If is not there then check if is set in HKEY_CLASSES_ROOT\ayon-launcher.
• If HKEY_CLASSES_ROOT\ayon-launcher is there and is correct then do nothing -> everything is set up.
• Otherwise set HKEY_CURRENT_USER\SOFTWARE\Classes\ayon-launcher.

It may also be based on install location (related to #169). If shim is installed to Program files then it must be added to HKEY_CURRENT_USER\SOFTWARE\Classes\ayon-launcher otherwise use only local override.