Bug fix for offline connectivity state

[sdbondi]

Description

Connectivity should only be considered Offline if there are zero
connections. Previously, the node could be considered offline if there
if there were no node connections, but some client connections were active.
This PR fixes that.

Motivation and Context

How Has This Been Tested?

Added a new test that fails for this bug

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Feature refactor (No new feature or functional changes, but performance or technical debt improvements)
• New Tests
• Documentation

Checklist:

• I'm merging against the development branch.
• I ran cargo-fmt --all before pushing.
• I ran cargo test successfully before submitting my PR.
• I have squashed my commits into a single commit.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.