Issue fix (456) for resolution of service account mapping (Translation of principals)

[grampurohitp]

• Please check if the PR fulfills these requirements
• [x] The commit messages are descriptive
• [x] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)
• [x] An issue has been created for the pull requests. Some issues might require previous discussion.

We couldn't find the existing testcase for CCloudAclsProvider and found it challenging to create one with CCloudApi not injected. So we have proposed a localised change and added test for the new code we introduced

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bug fix

• What is the current behavior? (You can also link to an open issue here)

• Documented under https://github.com/kafka-ops/julie/issues/456

• What is the new behavior (if this is a feature change)?

• Julie is now able to resolve the service accounts specified by name in the descriptor to the corresponding numeric id, so that the ACLs are created as expected

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

• Unlikely (this restores the ability of julie to function when the principal translation is enabled)

• Other information: We consider that the bug 456 is a show stopper for our use case where we expect to use the service account names (rather than numeric ids) and therefore we might require a new release/hot fix

[grampurohitp]

Thank you for your valuable comments @purbon , really appreciate your time

[purbon]

LGTM, thanks for the contribution!