Add support for configuration env and files section

clearml_agent/backend_api/config/default/agent.conf

@@ -221,4 +221,38 @@
     # Note: resulting name must start with an alphanumeric character and continue with alphanumeric characters,
     #  underscores (_), dots (.) and/or dashes (-)
     #docker_container_name_format: "clearml-id-{task_id}-{rand_string:.8}"
+
+    # Apply top-level environment section from configuration into os.environ
+    apply_environment: true
+    # Top-level environment section is in the form of:
+    #   environment {
+    #     key: value
+    #     ...
+    #   }
+    # and is applied to the OS environment as `key=value` for each key/value pair
+
+    # Apply top-level files section from configuration into local file system
+    apply_files: true
+    # Top-level files section allows auto-generating files at designated paths with a predefined contents
+    # and target format. Options include:
+    #  contents: the target file's content, typically a string (or any base type int/float/list/dict etc.)
+    #  format: a custom format for the contents. Currently supported value is `base64` to automatically decode a
+    #          base64-encoded contents string, otherwise ignored
+    #  path: the target file's path, may include ~ and inplace env vars
+    #  target_format: format used to encode contents before writing into the target file. Supported values are json,
+    #                 yaml, yml and bytes (in which case the file will be written in binary mode). Default is text mode.
+    #  overwrite: overwrite the target file in case it exists. Default is true.
+    #
+    # Example:
+    #   files {
+    #     myfile1 {
+    #       contents: "The quick brown fox jumped over the lazy dog"
+    #       path: "/tmp/fox.txt"
+    #     }
+    #     myjsonfile {
+    #       contents: {some: nested: value: [1, 2, 3, 4]}
+    #       path: "/tmp/test.json"
+    #       target_format: json
+    #     }
+    #   }
 }