Request - Add ability to specify per-machine or per-user installation via command line

[DanGough]

Justification
Currently the installer detects if running elevated and installs for all users if so. This presents 2 issues:

• When installing per-machine, the Uninstall reg key is still written to HKCU, so other users cannot see it in add/remove programs

• When trying to deploy this via Intune/ConfigMgr as a per-user app, if the user is an admin it will automatically run with highest available privileges. So you will end up with per-user installs on some devices and per-machine installs on other devices, depending on if the user had admin rights or not. IT admins need control over the installation context.

Description
I would like to be able to force override the installation context by specifying /ALLUSERS or /CURRENTUSER on the command line. I have seen many other InnoSetup installers do this (e.g. https://github.com/cthoeing/passwordtech).

Additionally, if installing for all users, the uninstall key should be written to HKLM rather than HKCU.