CI bsim workflow: Add UART tests to the bsim workflow

Add new workflow steps to the babblesim workflow to run
also the UART tests on the nrf52_bsim.
This commit:
* Enables the single device tests (which we may
move to the normal twister workflow once we fix the
requirement for a fixture)
* Adds as a placeholder the infra for multidevice tests.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>

tests/bsim/drivers/uart/compile.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# Copyright 2023 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+# Compile all the applications needed by all bsim UART tests
+
+#set -x #uncomment this line for debugging
+set -ue
+
+: "${BSIM_OUT_PATH:?BSIM_OUT_PATH must be defined}"
+: "${BSIM_COMPONENTS_PATH:?BSIM_COMPONENTS_PATH must be defined}"
+: "${ZEPHYR_BASE:?ZEPHYR_BASE must be set to point to the zephyr root\
+ directory}"
+
+WORK_DIR="${WORK_DIR:-${ZEPHYR_BASE}/bsim_out}"
+BOARD="${BOARD:-nrf52_bsim}"
+BOARD_ROOT="${BOARD_ROOT:-${ZEPHYR_BASE}}"
+
+mkdir -p ${WORK_DIR}
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+# Placeholder, nothing yet
+# Add apps needed for multidevice UART tests here
+
+wait_for_background_jobs