Implement external custom components installing from YAML (#1630)

* Move components import loading to importlib MetaPathFinder and importlib.resources

* Add external_components component

* Fix

* Fix

* fix cv.url return

* fix validate shorthand git

* implement git refresh

* Use finders from sys.path_hooks instead of looking for __init__.py

* use github:// schema

* error handling

* add test

* fix handling git output

* revert file check handling

* fix test

* allow full component path be specified for local

* fix test

* fix path handling

* lint

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

esphome/helpers.py

@@ -222,7 +222,7 @@ def write_file_if_changed(path: Union[Path, str], text: str):
         write_file(path, text)
 
 
-def copy_file_if_changed(src, dst):
+def copy_file_if_changed(src: os.PathLike, dst: os.PathLike) -> None:
     import shutil
 
     if file_compare(src, dst):
@@ -240,7 +240,7 @@ def list_starts_with(list_, sub):
     return len(sub) <= len(list_) and all(list_[i] == x for i, x in enumerate(sub))
 
 
-def file_compare(path1, path2):
+def file_compare(path1: os.PathLike, path2: os.PathLike) -> bool:
     """Return True if the files path1 and path2 have the same contents."""
     import stat