Magnifying or minifying a video using 🔍 will also start/stop the video

[Rillke]

Describe the bug
A clear and concise description of what you see:
When opening a published video on https://stable.opencast.org and clicking the 🔍 with a + or -, the video is magnified or minified but the playback state is also toggled (i.e. a playing video stops and a stopped video starts playing)

To Reproduce
Steps to reproduce the behavior:

1. Go to https://stable.opencast.org
2. Click on a published dual-stream video (Published: Yes -> Engange)
3. Start the video pressing the big play button ▶
4. Click the magnifying glass 🔍 on one video
5. The video stops if it was playing, or starts if it was not playing

Expected: Maginifcation/ minification without playback toggle

Environment Information

• OS: OSX Catalina
• Browser: Firefox 83.0 (64-Bit)
• Opencast 9.0.0.SNAPSHOT - 547d9ef
• Paella 6.4.3 (Opencast 9) and 6.4.4 (Paella Demo)

Additional info

This issue is reproducable on https://paellaplayer.upv.es/demos/ (6.4.4) and on Opencast r/8.x (with paella 6.2.7), but on r/8.x the issue occurs only once (i.e. even if you press the magnification glass multiple times after loading the page, the playback state is only toggled once)

A related issue: Pressing the magnifying glass twice may toggle the browser's full-screen state. So maybe an event.stopPropagation() is simply missing.