Externally visible changes:

• proto_common_do_not_use module is exposed with implementation matching Bazel@HEAD
• proto_lang_toolchain rule is extended with plugin_format_flag, progress_message, mnemonic, protocol_compiler attributes
• proto_lang_toolchain rules doesn't accept $(PLUGIN_OUT) placeholder (there are no uses on github)
• all fields in ProtoLangToolchainInfo are accessible in Starlark and the provider can be constructed
• ctx.actions.run and ctx.actions.run_shell accept resource_set parameter

Other invisible changes:

• proto_lang_toolchain rule is replaced with Starlark implementation
• ProtoLangToolchainInfo is implemented in Starlark
• Tests covering proto_common, proto_lang_toolchain rules are imported.
• Tests covering resource_set parameter

What's not changed:

• implementation of any other rules: proto_library, *_proto_library.

Cherry-picks for "Starlarkify proto_lang_toolchain rule":

• bb2e0ae Put protoc label to a constant.
• d69a55c Remove proto_lang_toolchain rule's $(PLUGIN_OUT) placeholder and simplify ProtoCompileActionBuilder.
• 45ce3dd Add plugin_format_flag attribute to ProtoLangToolchainRule
• 66e29cd Proxy proto compiler and proto opts over proto_lang_toolchain rule.
• b4587f8 Extend proto_lang_toolchain rule with progress_message and mnemonic attributes.
• 1e9a5de Starlarkify proto_lang_toolchain and ProtoLangToolchainInfo provider
• cbdb60c Roll forward of ae349e9: Export ProtoLangToolchainInfo provider and flip proto_lang_toolchain rule
• 8528661 Use data from transitive_proto_sources instead of transitive_sources in proto_lang_toolchain.
• 1d6ebeb Remove allow_files from proto_lang_toolchain's attributes
• eb251ca Remove native implementation of proto_lang_toolchain rule
• 8950863 Fix name in proto_lang_toolchain rule
• Cherry-pick missing things: ProtoCommon.checkPrivateStarlarkificationAllowlist and Starlark annotations in ProtoInfo and ProtoSource (mostly from 2a44dbd Implement proto_common.write_descriptor_set in Starlark.)

Cherry-picks for "Implement proto_common":

• 56d624b Separate ExecException.java from main actions target.
• d7f0724 ResourceSet in StarlarkAction API
  • Needed by proto_common.compile
• 982bbce Implement and expose proto_common.compile call.
• Fix ProtoCommon tests: some tests were disabled, because they cover bugs that were fixed during proto_library Starlarkificiation
• d7a3836 Add experimental_progress_message parameter to proto_common.compile.
• cf7ebef Implement proto_common.experimental_should_generate_code.
• e45fb7a Implement proto_common.declare_generated_files.
• bc1d31c Fix docstring in proto_common
• 4b7734c Add proto_info parameter to proto_common.compile
• 5aafdef Migrate proto_library_target to proto_info in proto_common.declare_generated_files.
• 1941e2b Migrate proto_library_target to proto_info in proto_common.experimental_should_generate_code
• caddaf1 Remove proto_library_target from proto_common