Port BlockBody functions to alloy

[mattsse]

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Describe the feature

we can reuse alloy's BlockBody type that is now identical to:

https://github.com/paradigmxyz/reth/blob/1e0a35e744633e605cf6ddd24f4b1c9d73b198c2/crates/primitives/src/block.rs#L577-L674

if we remove as many functions there as possible:

https://github.com/alloy-rs/alloy/blob/241bc6ea91042c2e43dc95cf39427622be179b59/crates/consensus/src/block.rs#L28-L37

some of them must be restricted to Transaction trait.

some might not be possible rn

Additional context

No response