Fix plugin for v0.16 of asdf and lts resolution

[taybart]

• Fixed permission issue on resolve command
• Fixed command names, removed .bash
  • https://asdf-vm.com/guide/upgrading-to-v0-16.html#extension-commands-have-been-redesigned
  • A more complete version of Update filemode of command-resolve.bash to support asdf 0.16.0 #410
• Fixed lts resolution (taken from fix: unable to resolve latest LTS version correctly #393 since that one seems stale)

I know this is duplicated stuff, but I just wanted the plugin working locally and these changes seem to fix everything for v0.16 that I ran into

[mikelkew]

@Stratus3D could you please review this PR when you get a chance? It's been necessary to use @taybart's fork to get the plugin to play nicely, even on the latest asdf v0.16.3