Added support for annotating rendered pip dependencies

[UebelAndre]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature (please, look at the "Scope of the project" section in the README.md file)
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

This change adds an annotations field to pip_parse and pip_install which allow users to make changes to generated python targets. The goal of this functionality is to allow users to filter out any non-determinsitic behavior they may find in their dependencies to resolve remote cache issues.

Issue Number: #571

What is the new behavior?

Below is an example of package_annotation. The rule allows us to add additional targets or set additional flags to packages like wheel in the example.

load("@rules_python//python:pip.bzl", "package_annotation", "pip_parse")

pip_parse(
    name = "pip_parsed",
    annotations = {
        "wheel": package_annotation(
            build_content = """\
load("@bazel_skylib//rules:write_file.bzl", "write_file")
write_file(
    name = "generated_file",
    out = "generated_file.txt",
    content = ["Hello world from build content file"],
)
""",
            copy_executables = {"@pip_repository_annotations_example//:data/copy_executable.py": "copied_content/executable.py"},
            copy_files = {"@pip_repository_annotations_example//:data/copy_file.txt": "copied_content/file.txt"},
            data = [":generated_file"],
            data_exclude_glob = ["*.dist-info/RECORD"],
        ),
    },
    requirements_lock = "//:requirements.txt",
)

The annotations here introduce the following changes to the BUILD file

diff --git a/BUILD.pip_parsed_wheel.bazel b/BUILD.pip_parsed_wheel.bazel
index 74dbeb0..8e3f483 100644
--- a/BUILD.pip_parsed_wheel.bazel
+++ b/BUILD.pip_parsed_wheel.bazel
@@ -22,7 +22,7 @@ filegroup(
 py_library(
     name = "pkg",
     srcs = glob(["**/*.py"], exclude=[], allow_empty = True),
-    data = [] + glob(["**/*"], exclude=["**/* *", "**/*.py", "**/*.pyc", "**/__pycache__/**", "*.whl", "BUILD.bazel", "WORKSPACE", "rules_python_wheel_entry_point*.py"]),
+    data = [":generated_file", "copied_content/executable.py", "copied_content/file.txt"] + glob(["**/*"], exclude=["**/* *", "**/*.py", "**/*.pyc", "**/__pycache__/**", "*.dist-info/RECORD", "*.whl", "BUILD.bazel", "WORKSPACE", "rules_python_wheel_entry_point*.py"]),
     # This makes this directory a top-level in the python import
     # search path for anything that depends on this.
     imports = ["."],
@@ -38,3 +38,24 @@ py_binary(
     imports = ["."],
     deps = ["pkg"],
 )
+
+copy_file(
+    name = "copied_content/file.txt.copy",
+    src = "@pip_repository_annotations_example//:data/copy_file.txt",
+    out = "copied_content/file.txt",
+    is_executable = False,
+)
+
+copy_file(
+    name = "copied_content/executable.py.copy",
+    src = "@pip_repository_annotations_example//:data/copy_executable.py",
+    out = "copied_content/executable.py",
+    is_executable = True,
+)
+
+load("@bazel_skylib//rules:write_file.bzl", "write_file")
+write_file(
+    name = "generated_file",
+    out = "generated_file.txt",
+    content = ["Hello world from build content file"],
+)

Does this PR introduce a breaking change?

• Yes
• No

Other information

[UebelAndre]

For better visibility, one issue came out of this PR: 7740b22#r64135831