Servo library support (#1343)

* ateempt at bringin servos

* basic plumbing

* avoid math map duplicate

* missing parts annontation

* pretify parts

* extend appcompat layer

* updated strings

* more compat layer

* annotations

* don't rely on webmidi

* updated pxt ref

* bump pxt

* adding whenUsed

* updated v1 readme

* more pins

* more pins

* compress the parts definition

* update common packages

pxtarget.json

@@ -9,7 +9,8 @@
         "libs/core",
         "libs/radio",
         "libs/devices",
-        "libs/bluetooth"
+        "libs/bluetooth",
+        "libs/servo"
     ],
     "cloud": {
         "workspace": false,