✨ Improve drop length display & recording date/time

[spikeheap]

This PR

• formats the drop length with minutes & seconds
• grabs the drop length when the media is loaded rather than on play
• adds the recording timestamp
• shifts the date/time formatting to the Vue component so we can use browser localisation

This should resolve the following from #1:

• Recording lengths not presented until played
• Recording lengths not presented in a sensible format
• Recording date doesn't show time

There's a momentary blip before the drop lengths are displayed because Howler needs to load the media. We could add some logic to show the drop only once it's been loaded.

Screen.Recording.2021-06-11.at.10.53.25.mov