[Feature]: Separate blocklist client responses from can-sign status

[djordon]

Feature - Separate blocklist client responses from can-sign status

1. Description

Currently, we don't use the blocklist client if the signer wasn't part of the signing set that created the deposit's aggregate key. By separating these, a signer could sign other digests within a transaction.

1.1 Context & Purpose

When deciding whether to sign transaction digests, signers need to know if they are part of the signing set that created the aggregate key and whether they wish to block the deposit. If all deposits are acceptable but a signer isn't part of the signing set locking some deposits, they should sign for the deposits that they can. The current code doesn't make that distinction possible.

2. Technical Details:

2.1 Acceptance Criteria:

• Always run the blocklist client for each deposit, not just ones that the signer can sign for.

3. Related Issues and Pull Requests (optional):

This came up as part of #798.