[ET-VK][ez] Update SDPA test to be able to test different SDPA modes

[SS-JIA]

Stack from ghstack (oldest at bottom):

• [ET-VK][ez] Don't copy zeros for cache tensors #15580
• [ET-VK][ez] SDPA don't branch based on whether bounds check needed #15579
• [ET-VK][ez] Align SDPA attention weights S dim to the next multiple of 4 #15578
• -> [ET-VK][ez] Update SDPA test to be able to test different SDPA modes #15577
• [ET-VK][ez] Refactor yaml configs for SDPA shaders #15576

Title says it all!

The purpose of this diff is twofold:

1. Test SDPA as both a fused operator (sdpa_with_kv_cache) and decomposed update_cache and custom_sdpa ops in order to detect possible regressions with being able to support older models
2. Make it easier to debug issues with SDPA by exposing a mode that tests only the attention weight computation.
   Title says it all! Update SDPA op to use buffer storage for cache tensors if projected tensors are buffer.

Also included is a small change to ensure that cache tensors use the same storage type as input tensors.

Differential Revision: D86226135

[pytorch-bot]

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✅ You can merge normally! (5 Unrelated Failures)

As of commit 8010c98 with merge base bde6b11 ():

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• pull / test-setup-linux-gcc / linux-job (gh) (similar failure)
  ##[error]The operation was canceled.

BROKEN TRUNK - The following jobs failed but was 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-openvino-linux / 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

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