Fix remote uninstall for dual launcher installations

[zackattack01]

We currently support remote uninstall (disable) here.
We also support manual uninstallation as a subcommand (for macOS and linux) here. Our manual uninstallation path attempts to pull the identifier out of the root directory path - so as long as this is invoked with a config or root directory argument, this already works as expected for dual installations.

We need to make similar adjustments for remote uninstallation, but this should be even easier than the manual path because it will only be invoked in situ (with access to knapsack and any identifier set in the config file). In general we should detect if a non-default identifier is set and:

• update the service name accordingly for windows, allowing the correct service to be set to manual start mode here
• interpolate the identifier into the macOS plist name here
• interpolate the identifier into the linux service name here

These changes should continue to default to the existing behavior unless a non-standard identifier is detected. These should be relatively low-risk changes, but should make release validation easier and without them it is possible for someone to trigger uninstall for the wrong launcher instance