Add graceful shutdown which stops jamid

Change-Id: I0268077ae05f84eb8c6e7fcbbf32ce2a562c7970
diff --git a/server/src/jamid/jami-swig.ts b/server/src/jamid/jami-swig.ts
index 3f48fbc..63fc307 100644
--- a/server/src/jamid/jami-swig.ts
+++ b/server/src/jamid/jami-swig.ts
@@ -51,6 +51,7 @@
 
 export interface JamiSwig {
   init(args: Record<string, unknown>): void;
+  fini(): void;
 
   // IntVect(): IntVect;
   // UintVect(): UintVect;
diff --git a/server/src/jamid/jamid.ts b/server/src/jamid/jamid.ts
index 5583f5c..b2d81c4 100644
--- a/server/src/jamid/jamid.ts
+++ b/server/src/jamid/jamid.ts
@@ -92,6 +92,10 @@
     this.jamid.init(handlers);
   }
 
+  stop() {
+    this.jamid.fini();
+  }
+
   getAccountList() {
     return stringVectToArr(this.jamid.getAccountList());
   }