BLE UART Buffer methods (#1353)

* adding simulator

* attempt at handling size

* correct ref counting

* defense is on

* handle read < 0

sim/state/misc.ts

@@ -208,6 +208,15 @@ namespace pxsim.bluetooth {
     export function uartWriteString(s: string): void {
         serial.writeString(s)
     }
+
+    export function uartWriteBuffer(b: RefBuffer): void {
+        serial.writeBuffer(b);
+    }
+
+    export function uartReadBuffer(): RefBuffer {
+        return pins.createBuffer(0);        
+    }
+
     export function uartReadUntil(del: string): string {
         return serial.readUntil(del);
     }