Add audit log

src/main/resources/db/migration/V7__channel_audit_log.sql

@@ -0,0 +1,12 @@
+CREATE TABLE IF NOT EXISTS channel_audit_log (
+    id TEXT PRIMARY KEY,
+    broadcaster TEXT NOT NULL,
+    actor TEXT,
+    action TEXT NOT NULL,
+    details TEXT,
+    created_at TIMESTAMP NOT NULL,
+    FOREIGN KEY (broadcaster) REFERENCES channels(broadcaster) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS channel_audit_log_broadcaster_idx ON channel_audit_log (broadcaster);
+CREATE INDEX IF NOT EXISTS channel_audit_log_created_at_idx ON channel_audit_log (created_at);