tests: group all build system tests under build_system

Consistent naming of components related to build system.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

tests/cmake/config_dir/testcase.yaml

@@ -1,5 +1,5 @@
 tests:
-  cmake.config_dir.user_defined:
+  buildsystem.config_dir.user_defined:
     platform_allow: native_posix
     build_only: true
     extra_args: APPLICATION_CONFIG_DIR:PATH=foo

tests/cmake/overlays/var_expansions/testcase.yaml

@@ -3,16 +3,16 @@ common:
   build_only: true
   platform_allow: native_posix
 tests:
-  cmake.overlays.var_expansions.CONF_FILE:
+  buildsystem.overlays.var_expansions.CONF_FILE:
     extra_conf_files:
       - ${ZEPHYR_MY_MODULE_NAME_MODULE_DIR}/zephyr/my_module-overlay.conf
       - ${ZEPHYR_MY_EXTRA_MODULE_NAME_MODULE_DIR}/zephyr/my_extra_module-overlay.conf
       - prj.conf
-  cmake.overlays.var_expansions.OVERLAY_CONFIG:
+  buildsystem.overlays.var_expansions.OVERLAY_CONFIG:
     extra_overlay_confs:
       - ${ZEPHYR_MY_MODULE_NAME_MODULE_DIR}/zephyr/my_module-overlay.conf
       - ${ZEPHYR_MY_EXTRA_MODULE_NAME_MODULE_DIR}/zephyr/my_extra_module-overlay.conf
-  cmake.overlays.var_expansions.DTC_OVERLAY_FILE:
+  buildsystem.overlays.var_expansions.DTC_OVERLAY_FILE:
     extra_dtc_overlay_files:
       - ${ZEPHYR_MY_MODULE_NAME_MODULE_DIR}/zephyr/my_module-board.overlay
       - ${ZEPHYR_MY_EXTRA_MODULE_NAME_MODULE_DIR}/zephyr/my_extra_module-board.overlay

tests/cmake/snippets/testcase.yaml

@@ -10,26 +10,26 @@ common:
 
 tests:
   # Test the initial state with no snippets applied
-  cmake.snippets.none:
+  buildsystem.snippets.none:
     extra_configs:
     - CONFIG_TEST_TYPE_NONE=y
   # Test the `foo` snippet from the default application snippet root
-  cmake.snippets.foo:
+  buildsystem.snippets.foo:
     extra_args: SNIPPET="foo"
     extra_configs:
     - CONFIG_TEST_TYPE_FOO=y
   # Test the `bar` snippet from an extra snippet root
-  cmake.snippets.bar:
+  buildsystem.snippets.bar:
     extra_args: SNIPPET="bar"
     extra_configs:
     - CONFIG_TEST_TYPE_BAR=y
   # Test the snippet processing order (1. foo, 2. bar)
-  cmake.snippets.foo_bar:
+  buildsystem.snippets.foo_bar:
     extra_args: SNIPPET="foo;bar"
     extra_configs:
     - CONFIG_TEST_TYPE_FOO_BAR=y
   # Test the snippet processing order (1. bar, 2. foo)
-  cmake.snippets.bar_foo:
+  buildsystem.snippets.bar_foo:
     extra_args: SNIPPET="bar;foo"
     extra_configs:
     - CONFIG_TEST_TYPE_BAR_FOO=y

tests/cmake/zephyr_get/testcase.yaml

@@ -3,9 +3,9 @@ common:
   build_only: true
   platform_allow: native_posix
 tests:
-  zephyr_get.no_sysbuild:
+  buildsystem.extensions.zephyr_get.no_sysbuild:
     sysbuild: false
-  zephyr_get.sysbuild:
+  buildsystem.extensions.zephyr_get.sysbuild:
     sysbuild: true
     extra_args: TESTCASE_VARIABLE="sysbuild.main"
       zephyr_get_2nd_TESTCASE_VARIABLE="sysbuild.2nd"