UI: move c-capnp to c++ (#1455)

* ui:move c-capnp to c++

* move Subsockets into vector

* rename reader to msg

include cereal/gen/cpp/log.capnp

* fix some errors

restore some changes

restore previous

* cleanup codes

cleanup codes

* remove unused variable alert_size

* handle capnproto's enum in a robust way

add break to default

* switch -> std:map

* use static std::map instead of switch

do cleanup

* fix wrong variable name

* use FlatArrayMessageReader instead of custom MessageReader

remove messagehelp.h

Revert "use FlatArrayMessageReader instead of custom MessageReader"

This reverts commit 57d8b6b1e2b4bad908246f35eb068535b1627167.

use FlatArrayMessageReader instead of custom MessageReader

add header file

remove capnp_c lib,add kj lib

include serialize.h

fix

remove duplicate includes
old-commit-hash: ee725534bb1ae2335705562e9f1eb176e5cd91fd

selfdrive/ui/SConscript

@@ -1,7 +1,7 @@
 Import('env', 'arch', 'common', 'messaging', 'gpucommon', 'visionipc', 'cereal')
 
 src = ['ui.cc', 'paint.cc', 'sidebar.cc', '#phonelibs/nanovg/nanovg.c']
-libs = [common, 'zmq', 'czmq', 'capnp', 'capnp_c', 'm', cereal, messaging, gpucommon, visionipc]
+libs = [common, 'zmq', 'czmq', 'capnp', 'kj', 'm', cereal, messaging, gpucommon, visionipc]
 
 if arch == "aarch64":
   src += ['sound.cc', 'slplay.c']