Support ledger friendly signatures in pallet-limit-orders

[girazoki]

Description

Before this PR the pallet-limit-orders only supports injecting the signature as the signature over the entire payload of the order.

After this PR the siganture of the form:

blake256(payload)

is also supported, as well as ed25519 signatures. the reason for this is that ledger wraps sigantures over these wrappers (and frankly, other offchain signing tools also might)

I maintained both for compatibility issues, but in theory the previous signature verification can be removed

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Other (please describe):

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have run ./scripts/fix_rust.sh to ensure my code is formatted and linted correctly
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules