feat(users/Profpatsch/lyric): add tapping & improve silence warning

Add a tapping command that does not quantize the timestamps.

For the silence warning, we make it BPM-dependent (defaulting to
120BPM as everywhere else), meaning for slower songs we give a higher
possible time difference before we display a warning.

Change-Id: Idefc44166639b23c2105a1a810ac22ed84457225
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12563
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI

users/Profpatsch/lyric/extension/package.json

@@ -30,6 +30,11 @@
         "title": "Shift Lyrics Up from Current Line",
         "category": "LRC"
       },
+      {
+        "command": "extension.tapBpm",
+        "title": "Add bpm header by tapping to the song",
+        "category": "LRC"
+      },
       {
         "command": "extension.quantizeToEigthNote",
         "title": "Quantize timestamps to nearest eighth note",