Adding support for Chatter keypad (#4022)

* Adding support for Chatter keypad

* Remove user button mapping since full keypad is now useable

* Adding TAB key and RIGHT to allow selecting a destination

* Fix shift bug (there's only three levels, not four)

* reformat file

* Fix bug with fast repeated keypresses

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/input/SerialKeyboard.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "InputBroker.h"
+#include "concurrency/OSThread.h"
+
+class SerialKeyboard : public Observable<const InputEvent *>, public concurrency::OSThread
+{
+  public:
+    explicit SerialKeyboard(const char *name);
+
+  protected:
+    virtual int32_t runOnce() override;
+    void erase();
+
+  private:
+    const char *_originName;
+    bool firstTime = 1;
+    int prevKeys = 0;
+    int keys = 0;
+    int shift = 0;
+    int keyPressed = 13;
+    int lastKeyPressed = 13;
+    int quickPress = 0;
+    unsigned long lastPressTime = 0;
+};