Merge 'parent' and 'name' columns into 'path' (#101)

* Merge `File.parent` and `File.name` into `File.path`
* Add back `File.name` and `File.parent` as properties
* Update file cache key
* Merge `parent` and `name` columns in internal tables
* Merge `parent` and `name` attributes into `path` for internal classes `UniqueId`, `Entry` and `Node`
* Update all examples

Author: rlamy

examples/computer_vision/blip2_image_desc_lib.py

@@ -86,7 +86,7 @@ def process(self, file):
 if __name__ == "__main__":
     (
         DataChain.from_storage(source, type="image")
-        .filter(C("file.name").glob("cat*.jpg"))
+        .filter(C("file.path").glob("*/cat*.jpg"))
         .map(
             desc=BLIP2Describe(
                 # device=device,
@@ -95,8 +95,6 @@ def process(self, file):
             params=["file"],
             output={"description": str, "error": str},
         )
-        .select(
-            "file.source", "file.parent", "file.name", "desc.description", "desc.error"
-        )
+        .select("file.source", "file.path", "desc.description", "desc.error")
         .show(5)
     )