Vendorize uClock (#10)

Add copy of uClock to the repo including memory optimization changes.

Also add user config setting for changing Pulse Out resolution.

Reviewed-on: https://git.pinkduck.xyz/adam/libGravity/pulls/10
Co-authored-by: Adam Wonak <adam.wonak@gmail.com>
Co-committed-by: Adam Wonak <adam.wonak@gmail.com>

examples/Gravity/save_state.h

@@ -54,6 +54,7 @@ class StateManager {
         byte selected_param;
         byte selected_channel;
         byte selected_source;
+        byte selected_pulse;
         ChannelState channel_data[Gravity::OUTPUT_COUNT];
     };