Refactor czi_hosted and server into backend directory, pull common code into backend/common, refactor tests (#2102)

* move local_server -> backend/server server-> backend/czi_hosted, pull common code into backend/common update imports, tests and make commands

backend/test/test_server/unit/cli/test_launch.py

@@ -0,0 +1,27 @@
+import filecmp
+import os
+import shutil
+import unittest
+
+import yaml
+
+from backend.server.default_config import default_config
+from backend.test import FIXTURES_ROOT
+
+
+class CLIPLaunchTests(unittest.TestCase):
+    tmp_dir = os.path.join(FIXTURES_ROOT, "dump_configs")
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        os.mkdir(cls.tmp_dir)
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        shutil.rmtree(cls.tmp_dir)
+
+    def test_dump_default_config(self):
+        os.system(f"cellxgene launch --dump-default-config > {self.tmp_dir}/test_config_dump.txt")
+        with open(f"{self.tmp_dir}/expected_config_dump.txt", "w") as expected_config:
+            expected_config.write(yaml.dump(default_config))
+        filecmp.cmp(f"{self.tmp_dir}/expected_config_dump.txt", f"{self.tmp_dir}/test_config_dump.txt")