Try to get the `.editorconfig` and `.prettierrc` files as close as possible
to the formatting that was used in Flamenco. Because these files weren't
here during most of Flamenco's development so far, having them caused quite
a few changes in the webapp files.
No functional changes intended.
Replace the Vue v2 webapp with a Vue v3 one, and embed the OpenAPI
client in the webapp itself (instead of being its own npm project).
- Vue v2.x -> v3.x
- Tabulator v4.x -> v5.1
- Moment JS -> replaced with Luxon JS
- Vue CLI/UI -> replaced with Vite
