Add EgressSourceType to EgressInfo (#894)

* WiP

* Define EgressSourceType and record it in the EgressInfo for proper biling

* generated protobuf

* Create shy-planets-impress.md

* generated protobuf

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Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

Author: biglittlebigben

.changeset/shy-planets-impress.md

@@ -0,0 +1,5 @@
+---
+"@livekit/protocol": patch
+---
+
+Add EgressSourceType to EgressInfo