Ser correct byte prefix for SlashLogKey

[mpoke]

Description

Replace SlashAcksBytePrefix with SlashLogBytePrefix

Linked issues

Closes: #785

Type of change

If you've checked more than one of the first three boxes, consider splitting this PR into multiple PRs!

• Feature: Changes and/or adds code behavior, irrelevant to bug fixes
• Fix: Changes and/or adds code behavior, specifically to fix a bug
• Refactor: Changes existing code style, naming, structure, etc.
• Testing: Adds testing
• Docs: Adds documentation

New behavior tests

If Feature or Fix, describe the new or existing tests that verify the new behavior is correct and expected.

Versioning Implications

• This PR will affect semantic versioning as defined for ICS

If the above box is checked, which version should be bumped?

• MAJOR: Consensus breaking changes to both the provider and consumers(s), including updates/breaking changes to IBC communication between provider and consumer(s)
• MINOR: Consensus breaking changes which affect either only the provider or only the consumer(s)
• PATCH: Non consensus breaking changes

Targeting

Please select one of the following:

• This PR is only relevant to main
• This PR is relevant to main, and should also be back-ported to ____ (ex: v1.0.0 and v1.1.0)
• This PR is only relevant to ____ (ex: v1.0.0, v1.1.0, and v1.2.0)