feat: Per-sequence scaling in FP8 attention, FP8 fixes

[ani300]

Description of the change

• Per-sequence scaling in FP8 attention for both static and continuous batching
• FP8 fixes for the CPU fallback in both eager and torch compile modes

Related issues or PRs

Internal to IBM issue

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[andrea-fasoli]

tested the fp8_spyre_op fix locally and confirm it addresses the _scaled_mm issue when compiling the model.
Waiting for further tests before merging.

[andrea-fasoli]

tested as functional