feat: create and remove multi word glosses

[arrocke]

What has changed

• Routes to add and delete phrases
• UI to select words to link in a phrase, link and unlink words, show words linked to current word
• Keyboard shortcuts to select words, link and unlink

Connected Issues

closes #377

QA Steps

1. Use the checkbox and Ctrl+Enter the select/deselect words
2. Use the link words button and Ctrl+L to link selected words
3. Use the unlink words button and Ctrl+U to unlink selected words
4. Confirm that linked words can't be selected to form new phrases
5. Confirm that linked words show background when one of the words in the phrase is highlighted

Post-Deployment

• [x] Nothing required

[arrocke]

Here are my thoughts:

1. Yes. This will especially be true for greek where words can be reordered in interesting ways. This system is designed to handle that by allowing you to select any set of words in the verse to link together
2. If you entered a gloss for words that you linked together, I don't think that's going to be useful if you change your mind that they aren't associated. We will definitely revisit this if we get feedback from translators
3. Yep, this is a good idea
4. I actually started with shift+click, the main issue with that is discoverability. By showing a checkbox on hover and focus, you make it clear to the user that selection is possible. It's the same problem with using Enter to approve glosses. Users don't know that's possible unless you show them.