feat(tar): add ergonomic way to strip_prefix

[alexeagle]

The genrule we used was too complex to ask users to copy-paste it

This is a partial step to exposing a rules_pkg pkg_tar compatible API.

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Changes are visible to end-users: yes

• Searched for relevant documentation and updated as needed: yes
• Breaking change (forces users to change their own code or config): no
• Suggested release notes appear below: yes

The tar package now provides a new mtree_mutate macro which allows a more ergonomic equivalent of pkg_tar attributes like strip_prefix, uid, and more.

Test plan

• New test cases added

[aspect-workflows[bot]]

Test

4 test targets passed

Targets

//docs:update_11_test [k8-opt]                         120ms
//lib/tests/copy_to_directory_bin_action:test [k8-opt] 29ms
//lib/tests/jq:check_stamped [k8-opt]                  28ms
//lib/tests/yq:check_stamped [k8-opt]                  32ms

Total test execution time was 209ms. 225 tests (98.3%) were fully cached saving 38s.

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Test

e2e/copy_to_directory

All tests were cache hits

6 tests (100.0%) were fully cached saving 660ms.

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Test

e2e/coreutils

All tests were cache hits

4 tests (100.0%) were fully cached saving 578ms.

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Test

e2e/external_copy_to_directory

All tests were cache hits

1 test (100.0%) was fully cached saving 52ms.

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Test

e2e/smoke

All tests were cache hits

6 tests (100.0%) were fully cached saving 1s.

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Buildifier      Format      Gazelle