fix(protocol-kit): Fix signature generation for multiple contract signatures

[sidnym-ladrut]

What it solves

There are currently a few minor issues in protocol-kit related to contract signatures (i.e. EIP-1271):

1. Contract signatures processed by the API are not recognized as such (fix in Safe.ts).
2. The dynamic part of a contract signature is calculated as the entire segment of the given data, when it should be the last 97 bytes only (65 bytes signature + 32 bytes length).

How this PR fixes it

These issues are fixed in the following ways:

1. All CONTRACT_SIGNATURE responses are registered as contract signatures.
2. The dynamic part of contract signatures is adjusted to be the last 97 bytes of the data payload.

[github-actions]

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[sidnym-ladrut]

I have read the CLA Document and I hereby sign the CLA