[OSCBS-41] Update to Zephyr v3.2.0 (#382)

Updating to integrate with Zephyr v3.2.0 required:

- Update `west.yml` to import Zephyr v3.2.0 manifest
- Prefix include pathname of ztest.h with `zephyr/`
- Prefix every Zephyr header included pathname with `zephyr/`
- Change all Zephyr tests/samples to use `find_package`
- For unit_testing, use a distinct prj.conf which only references
  Kconfigs defined in the Zephyr repo. (Zephyr constraint.)
- Move ztest headers into a zephyr-prefixed pathname

Co-authored-by: Gregory Shue <gregory.shue@legrand.com>

zephyr/tests/bacnet/datalink/mock/prj.unit_testing.conf

@@ -0,0 +1,27 @@
+CONFIG_ZTEST=y
+#CONFIG_BACNETSTACK=y
+CONFIG_ZTEST_MOCKING=y
+
+## BIP Options
+#CONFIG_BACDL_BIP=n
+##CONFIG_BACDL_BIP_PORT=47808
+##CONFIG_BACDL_BIP_ADDRESS_INDEX=0
+
+# pthreads
+#CONFIG_POSIX_API=y
+#CONFIG_PTHREAD_IPC=y
+#CONFIG_POSIX_MQUEUE=y
+
+# networking
+CONFIG_NETWORKING=y
+CONFIG_NET_IPV4=y
+CONFIG_NET_ARP=y
+CONFIG_NET_TCP=y
+CONFIG_NET_UDP=y
+CONFIG_NET_DHCPV4=y
+CONFIG_NET_L2_ETHERNET=n
+
+CONFIG_NET_MGMT=y
+CONFIG_NET_MGMT_EVENT=y
+
+CONFIG_LOG=y