Manage exceptions in `JwsIssuer`

[ndr-brt]

Feature Request

As stated by this TODO:

Connector/extensions/common/crypto/lib/jws2020-lib/src/main/java/org/eclipse/edc/security/signature/jws2020/JwsIssuer.java

Line 58 in 9bcce99

// TODO do something with exceptions, unify

Which Areas Would Be Affected?

e.g., DPF, CI, build, transfer, etc.

Why Is the Feature Desired?

Are there any requirements?

Who will sponsor this feature?

Please @-mention the committer that will sponsor your feature.

Solution Proposal

If possible, provide a (brief!) solution proposal.