Installer doesn't differentiate different node installations

[cwernert]

MacOS can have node in various spots, and it looks like (verify) SwiftBar requires it to be in the standard dir:
/usr/local/bin/node
If Node is installed via NVM, it will be at:
~/.nvm/versions/node

Need to:

• Verify that swiftbar needs node in the standard dir
• Update the installer to check for and enforce this

[cwernert]

Might be able to do this simply by expecting this result from which node:
/usr/local/bin/node

[cwernert]

Also not sure if relevant, but the shebang seems to be the reason the plugin throws an error - maybe this could be set dynamically?
#!/usr/bin/env /usr/local/bin/node

[cwernert]

I reduced the specificity of the shebang on both node js files, so that instead of referring to node with an absolute path, it now relies on env finding the user's node installation. Dayne will test this when reinstalling