[bazel] add python targets (#101003)

This PR adds bazel python, so that bazel build could be used from python like `import torch`.

Notable changes:
- Add the python targets.
- Add the version.py.tpl generation.
- In order to archive the `USE_GLOBAL_DEPS = False` just for the bazel build, employ a monkey-patch hack in the mentioned `version.py.tpl`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/101003
Approved by: https://github.com/huydhn

WORKSPACE

@@ -54,6 +54,13 @@ http_archive(
     urls = [
         "https://github.com/google/glog/archive/v0.4.0.tar.gz",
     ],
+    build_file_content = """
+licenses(['notice'])
+
+load(':bazel/glog.bzl', 'glog_library')
+# TODO: figure out why enabling gflags leads to SIGSEV on the logging init
+glog_library(with_gflags=0)
+    """
 )
 
 http_archive(