API sync

[defagos]

• [x] Shouldn't we send the app friendly name as well for more readable reporting?
• [x] Should we send the frame drops as well as the total played frames? The motivation is that during a painful live stream event we had a lot of dropped frames.
• [x] Discuss naming conventions (see https://github.com/SRGSSR/pillarbox-documentation/pull/96#pullrequestreview-2275519332)

[defagos]

• App friendly name: Not useful, we can add a mapping on Grafana.
• Frame drops: Total may be sent in status events if available. Field name frame_drops, integer.
• ~Uppercase for all enum values (e.g. stream type, event name, etc.). If better formatting is required add a mapping on Grafana.~ Uppercase for event names only, otherwise rule is "as readable as possible" (start with uppercase letter in general, except if brand name says otherwise. Values extracted from the system unchanged.