Arm backend: Initial support of conditional operator

[Erik-Lundell]

- Add partition check to make sure that the submodules with
the if/else codepaths are fully delegated.
- Fix some partitioning issues with submodule nodes, since they
point to a submodule rather than a tensor they dont have a fake tensor.
- Add node visitor.
- Add tests.

Arm backend: Use output.name in node visitors

As mentioned in #15381, TOSA tensors need unique naming,
which gets tricky with submodules. It is handled in
the TosaArg object, and therefore node visitors need
to use output.name rather than node.name when creating
new tensors.

cc @freddan80 @per @zingo @oscarandersson8218 @digantdesai

[pytorch-bot]

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✅ You can merge normally! (7 Unrelated Failures)

As of commit 7198aa0 with merge base 4ea9ddf ():

FLAKY - The following jobs failed but were likely due to flakiness present on trunk:

• pull / test-openvino-linux / linux-job (gh) (similar failure)
  ##[error]The operation was canceled.
• trunk / test-qnn-model (fp32, conv_former) / linux-job (gh) (matched linux rule in flaky-rules.json)
  The process '/usr/bin/git' failed with exit code 128

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / test-binary-size-linux-gcc / linux-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / test-setup-linux-gcc / linux-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest / windows / windows-job (gh) (trunk failure)
  backends/xnnpack/test/ops/test_conv1d.py::TestConv1d::test_qs8_conv1d_batchnorm_seq
• pull / unittest-editable / windows / windows-job (gh) (trunk failure)
  backends/xnnpack/test/ops/test_conv1d.py::TestConv1d::test_qs8_conv1d_batchnorm_seq
• trunk / unittest-release / windows / windows-job (gh) (trunk failure)
  backends/xnnpack/test/ops/test_conv1d.py::TestConv1d::test_qs8_conv1d_batchnorm_seq

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[zingo]

Hi again @SS-JIA here is a lager patch touching many file. Sorry we got so many in a row right now, it's usually calmer :)

[zingo]

@SS-JIA we think this should be buck2 build safe as the new cond op should be handled by the
srcs = glob(["op_.py", "ops_.py"]), rule.

[SS-JIA]

Should be okay!

[zingo]

Failed tests seems unrelated