Fixed

• Fixed issue with nrfutil install cmd1 cmd2 ... breaking off too early if a command already is installed.
• Reduced the CPU usage when a long running command such as nrfutil toolchain-manager launch is started by nRF Util.
• Fixed behavior where self-upgrade would downgrade the installed core package if it was the latest version of the core package on the targeted package registry. Now it will refuse but can still be made to do the install with the --force flag.
• If the user force installs a specific version of an nRF Util package but that version didn't exist on the package index, then previously the local version would be uninstalled and then the new install would fail. Now the package index is checked first and an error is raised before the local version is uninstalled so the user is not left without a version entirely.