[tsslib]Sigma audit feedback, MNT-09: Lack Of Signature Size Verification Checks

[abelliumnt]

Describe the bug
Multiple instances of lack of signature’s size verification before use have been identified:

Expected behavior
Implement additional checks on the signature length prior to taking a slice of the signature bytes or performing any indexing operations.

Screenshots
tss/ws/server/handler.go

tss/manager/sign.go

datalayr-mantle/common/contracts/utils.go