[Input] Add selectors

[zeh]

When using a command, we should also be able to select entries from a "selector", like a combo box. For example, when using -preset, the actual parameter (veryslow, slow, fast, etc) should come from a selector.

Requirements

• Create a new field type, e.g. {{{selector}}}
  • Must allow several entries
  • Must allow a with an optional display label
  • Must allow a default, or none
• Create input field renderer component that allows selections
• Add it to existing selectors where appropriate in commands.json

[zeh]

Deployed in 52b90cc.